diff --git a/src/commonMain/kotlin/fr/acinq/lightning/channel/Channel.kt b/src/commonMain/kotlin/fr/acinq/lightning/channel/Channel.kt
index 24ae556fc..15c0fb9cf 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/channel/Channel.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/channel/Channel.kt
@@ -1003,7 +1003,7 @@ data class Syncing(val state: ChannelStateWithCommitments, val waitForTheirReest
                             state.commitments,
                             state.localShutdown.scriptPubKey.toByteArray(),
                             state.remoteShutdown.scriptPubKey.toByteArray(),
-                            currentOnChainFeerates.mutualCloseFeerate
+                            state.closingFeerates ?: ClosingFeerates(currentOnChainFeerates.mutualCloseFeerate)
                         )
                         val closingTxProposed1 = state.closingTxProposed + listOf(listOf(ClosingTxProposed(closingTx, closingSigned)))
                         val nextState = state.copy(closingTxProposed = closingTxProposed1)
@@ -1774,6 +1774,7 @@ data class WaitForFundingLocked(
                         initialChannelUpdate,
                         null,
                         null,
+                        null,
                         null
                     )
                     val actions = listOf(
@@ -1826,7 +1827,8 @@ data class Normal(
     val channelUpdate: ChannelUpdate,
     val remoteChannelUpdate: ChannelUpdate?,
     val localShutdown: Shutdown?,
-    val remoteShutdown: Shutdown?
+    val remoteShutdown: Shutdown?,
+    val closingFeerates: ClosingFeerates?
 ) : ChannelStateWithCommitments() {
     override fun updateCommitments(input: Commitments): ChannelStateWithCommitments = this.copy(commitments = input)
 
@@ -1889,7 +1891,7 @@ data class Normal(
                             !Helpers.Closing.isValidFinalScriptPubkey(localScriptPubkey) -> handleCommandError(event.command, InvalidFinalScript(channelId), channelUpdate)
                             else -> {
                                 val shutdown = Shutdown(channelId, localScriptPubkey)
-                                val newState = this.copy(localShutdown = shutdown)
+                                val newState = this.copy(localShutdown = shutdown, closingFeerates = event.command.feerates)
                                 val actions = listOf(ChannelAction.Storage.StoreState(newState), ChannelAction.Message.Send(shutdown))
                                 Pair(newState, actions)
                             }
@@ -1956,7 +1958,7 @@ data class Normal(
 
                                 if (commitments1.remoteCommit.spec.htlcs.isNotEmpty()) {
                                     // we just signed htlcs that need to be resolved now
-                                    ShuttingDown(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown)
+                                    ShuttingDown(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown, closingFeerates)
                                 } else {
                                     logger.warning { "c:$channelId we have no htlcs but have not replied with our Shutdown yet, this should never happen" }
                                     val closingTxProposed = if (isFunder) {
@@ -1965,13 +1967,13 @@ data class Normal(
                                             commitments1,
                                             localShutdown.scriptPubKey.toByteArray(),
                                             remoteShutdown.scriptPubKey.toByteArray(),
-                                            currentOnChainFeerates.mutualCloseFeerate,
+                                            closingFeerates ?: ClosingFeerates(currentOnChainFeerates.mutualCloseFeerate),
                                         )
                                         listOf(listOf(ClosingTxProposed(closingTx, closingSigned)))
                                     } else {
                                         listOf(listOf())
                                     }
-                                    Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown, closingTxProposed, bestUnpublishedClosingTx = null)
+                                    Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown, closingTxProposed, bestUnpublishedClosingTx = null, closingFeerates)
                                 }
                             } else {
                                 this.copy(commitments = commitments1)
@@ -2037,7 +2039,7 @@ data class Normal(
                                             commitments1,
                                             localShutdown.scriptPubKey.toByteArray(),
                                             event.message.scriptPubKey.toByteArray(),
-                                            currentOnChainFeerates.mutualCloseFeerate,
+                                            closingFeerates ?: ClosingFeerates(currentOnChainFeerates.mutualCloseFeerate),
                                         )
                                         val nextState = Negotiating(
                                             staticParams,
@@ -2047,19 +2049,20 @@ data class Normal(
                                             localShutdown,
                                             event.message,
                                             listOf(listOf(ClosingTxProposed(closingTx, closingSigned))),
-                                            bestUnpublishedClosingTx = null
+                                            bestUnpublishedClosingTx = null,
+                                            closingFeerates
                                         )
                                         actions.addAll(listOf(ChannelAction.Storage.StoreState(nextState), ChannelAction.Message.Send(closingSigned)))
                                         Pair(nextState, actions)
                                     }
                                     commitments1.hasNoPendingHtlcsOrFeeUpdate() -> {
-                                        val nextState = Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, event.message, closingTxProposed = listOf(listOf()), bestUnpublishedClosingTx = null)
+                                        val nextState = Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, event.message, listOf(listOf()), null, closingFeerates)
                                         actions.add(ChannelAction.Storage.StoreState(nextState))
                                         Pair(nextState, actions)
                                     }
                                     else -> {
                                         // there are some pending changes, we need to wait for them to be settled (fail/fulfill htlcs and sign fee updates)
-                                        val nextState = ShuttingDown(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, event.message)
+                                        val nextState = ShuttingDown(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, event.message, closingFeerates)
                                         actions.add(ChannelAction.Storage.StoreState(nextState))
                                         Pair(nextState, actions)
                                     }
@@ -2137,7 +2140,8 @@ data class ShuttingDown(
     override val currentOnChainFeerates: OnChainFeerates,
     override val commitments: Commitments,
     val localShutdown: Shutdown,
-    val remoteShutdown: Shutdown
+    val remoteShutdown: Shutdown,
+    val closingFeerates: ClosingFeerates?
 ) : ChannelStateWithCommitments() {
     override fun updateCommitments(input: Commitments): ChannelStateWithCommitments = this.copy(commitments = input)
 
@@ -2176,7 +2180,7 @@ data class ShuttingDown(
                                         commitments1,
                                         localShutdown.scriptPubKey.toByteArray(),
                                         remoteShutdown.scriptPubKey.toByteArray(),
-                                        currentOnChainFeerates.mutualCloseFeerate
+                                        closingFeerates ?: ClosingFeerates(currentOnChainFeerates.mutualCloseFeerate)
                                     )
                                     val nextState = Negotiating(
                                         staticParams,
@@ -2186,7 +2190,8 @@ data class ShuttingDown(
                                         localShutdown,
                                         remoteShutdown,
                                         listOf(listOf(ClosingTxProposed(closingTx, closingSigned))),
-                                        bestUnpublishedClosingTx = null
+                                        bestUnpublishedClosingTx = null,
+                                        closingFeerates
                                     )
                                     val actions = listOf(
                                         ChannelAction.Storage.StoreState(nextState),
@@ -2196,7 +2201,7 @@ data class ShuttingDown(
                                     Pair(nextState, actions)
                                 }
                                 commitments1.hasNoPendingHtlcsOrFeeUpdate() -> {
-                                    val nextState = Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown, closingTxProposed = listOf(listOf()), bestUnpublishedClosingTx = null)
+                                    val nextState = Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown, listOf(listOf()), null, closingFeerates)
                                     val actions = listOf(ChannelAction.Storage.StoreState(nextState), ChannelAction.Message.Send(revocation))
                                     Pair(nextState, actions)
                                 }
@@ -2224,7 +2229,7 @@ data class ShuttingDown(
                                         commitments1,
                                         localShutdown.scriptPubKey.toByteArray(),
                                         remoteShutdown.scriptPubKey.toByteArray(),
-                                        currentOnChainFeerates.mutualCloseFeerate
+                                        closingFeerates ?: ClosingFeerates(currentOnChainFeerates.mutualCloseFeerate)
                                     )
                                     val nextState = Negotiating(
                                         staticParams,
@@ -2234,13 +2239,14 @@ data class ShuttingDown(
                                         localShutdown,
                                         remoteShutdown,
                                         listOf(listOf(ClosingTxProposed(closingTx, closingSigned))),
-                                        bestUnpublishedClosingTx = null
+                                        bestUnpublishedClosingTx = null,
+                                        closingFeerates
                                     )
                                     actions1.addAll(listOf(ChannelAction.Storage.StoreState(nextState), ChannelAction.Message.Send(closingSigned)))
                                     Pair(nextState, actions1)
                                 }
                                 commitments1.hasNoPendingHtlcsOrFeeUpdate() -> {
-                                    val nextState = Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown, closingTxProposed = listOf(listOf()), bestUnpublishedClosingTx = null)
+                                    val nextState = Negotiating(staticParams, currentTip, currentOnChainFeerates, commitments1, localShutdown, remoteShutdown, listOf(listOf()), null, closingFeerates)
                                     actions1.add(ChannelAction.Storage.StoreState(nextState))
                                     Pair(nextState, actions1)
                                 }
@@ -2350,7 +2356,8 @@ data class Negotiating(
     val localShutdown: Shutdown,
     val remoteShutdown: Shutdown,
     val closingTxProposed: List<List<ClosingTxProposed>>, // one list for every negotiation (there can be several in case of disconnection)
-    val bestUnpublishedClosingTx: ClosingTx?
+    val bestUnpublishedClosingTx: ClosingTx?,
+    val closingFeerates: ClosingFeerates?
 ) : ChannelStateWithCommitments() {
     init {
         require(closingTxProposed.isNotEmpty()) { "there must always be a list for the current negotiation" }
@@ -2362,82 +2369,108 @@ data class Negotiating(
     override fun processInternal(event: ChannelEvent): Pair<ChannelState, List<ChannelAction>> {
         return when {
             event is ChannelEvent.MessageReceived && event.message is ClosingSigned -> {
-                logger.info { "c:$channelId received closingFeeSatoshis=${event.message.feeSatoshis}" }
-                val checkSig = Helpers.Closing.checkClosingSignature(keyManager, commitments, localShutdown.scriptPubKey.toByteArray(), remoteShutdown.scriptPubKey.toByteArray(), event.message.feeSatoshis, event.message.signature)
-                val lastLocalClosingFee = closingTxProposed.last().lastOrNull()?.localClosingSigned?.feeSatoshis
-                val nextClosingFee = if (commitments.localCommit.spec.toLocal == 0.msat) {
-                    // if we have nothing at stake there is no need to negotiate and we accept their fee right away
-                    event.message.feeSatoshis
-                } else {
-                    Helpers.Closing.nextClosingFee(
-                        lastLocalClosingFee ?: Helpers.Closing.firstClosingFee(commitments, localShutdown.scriptPubKey, remoteShutdown.scriptPubKey, currentOnChainFeerates.mutualCloseFeerate),
-                        event.message.feeSatoshis
-                    )
-                }
-                val result = checkSig.map { signedClosingTx -> // this signed closing tx matches event.message.feeSatoshis
-                    when {
-                        lastLocalClosingFee == event.message.feeSatoshis || lastLocalClosingFee == nextClosingFee || closingTxProposed.flatten().size >= MAX_NEGOTIATION_ITERATIONS -> {
-                            logger.info { "c:$channelId closing tx published: closingTxId=${signedClosingTx.tx.txid}" }
-                            val nextState = Closing(
-                                staticParams,
-                                currentTip,
-                                currentOnChainFeerates,
-                                commitments,
-                                fundingTx = null,
-                                waitingSinceBlock = currentBlockHeight.toLong(),
-                                mutualCloseProposed = this.closingTxProposed.flatten().map { it.unsignedTx },
-                                mutualClosePublished = listOf(signedClosingTx)
-                            )
-                            val actions = listOf(
-                                ChannelAction.Storage.StoreState(nextState),
-                                ChannelAction.Blockchain.PublishTx(signedClosingTx.tx),
-                                ChannelAction.Blockchain.SendWatch(WatchConfirmed(channelId, signedClosingTx.tx, staticParams.nodeParams.minDepthBlocks.toLong(), BITCOIN_TX_CONFIRMED(signedClosingTx.tx)))
-                            )
-                            Pair(nextState, actions)
-                        }
-                        nextClosingFee == event.message.feeSatoshis -> {
-                            // we have converged but they don't have our signature yet
-                            logger.info { "c:$channelId closing tx published: closingTxId=${signedClosingTx.tx.txid}" }
-                            val (_, closingSigned) = Helpers.Closing.makeClosingTx(keyManager, commitments, localShutdown.scriptPubKey.toByteArray(), remoteShutdown.scriptPubKey.toByteArray(), nextClosingFee)
-                            val nextState = Closing(
-                                staticParams,
-                                currentTip,
-                                currentOnChainFeerates,
-                                commitments,
-                                fundingTx = null,
-                                waitingSinceBlock = currentBlockHeight.toLong(),
-                                mutualCloseProposed = this.closingTxProposed.flatten().map { it.unsignedTx } + listOf(signedClosingTx),
-                                mutualClosePublished = listOf(signedClosingTx)
-                            )
-                            val actions = listOf(
-                                ChannelAction.Storage.StoreState(nextState),
-                                ChannelAction.Blockchain.PublishTx(signedClosingTx.tx),
-                                ChannelAction.Blockchain.SendWatch(WatchConfirmed(channelId, signedClosingTx.tx, staticParams.nodeParams.minDepthBlocks.toLong(), BITCOIN_TX_CONFIRMED(signedClosingTx.tx))),
-                                ChannelAction.Message.Send(closingSigned)
-                            )
-                            Pair(nextState, actions)
-                        }
-                        else -> {
-                            val (closingTx, closingSigned) = Helpers.Closing.makeClosingTx(keyManager, commitments, localShutdown.scriptPubKey.toByteArray(), remoteShutdown.scriptPubKey.toByteArray(), nextClosingFee)
-                            logger.info { "c:$channelId proposing closingFeeSatoshis=${closingSigned.feeSatoshis}" }
-                            val closingProposed1 = closingTxProposed.updated(
-                                closingTxProposed.lastIndex,
-                                closingTxProposed.last() + listOf(ClosingTxProposed(closingTx, closingSigned))
-                            )
-                            val nextState = this.copy(
-                                commitments = commitments.copy(remoteChannelData = event.message.channelData),
-                                closingTxProposed = closingProposed1,
-                                bestUnpublishedClosingTx = closingTx
-                            )
-                            val actions = listOf(ChannelAction.Storage.StoreState(nextState), ChannelAction.Message.Send(closingSigned))
-                            Pair(nextState, actions)
+                val remoteClosingFee = event.message.feeSatoshis
+                logger.info { "c:$channelId received closing fee=$remoteClosingFee" }
+                when (val result = Helpers.Closing.checkClosingSignature(keyManager, commitments, localShutdown.scriptPubKey.toByteArray(), remoteShutdown.scriptPubKey.toByteArray(), event.message.feeSatoshis, event.message.signature)) {
+                    is Either.Left -> handleLocalError(event, result.value)
+                    is Either.Right -> {
+                        val (signedClosingTx, closingSignedRemoteFees) = result.value
+                        val lastLocalClosingSigned = closingTxProposed.last().lastOrNull()?.localClosingSigned
+                        when {
+                            lastLocalClosingSigned?.feeSatoshis == remoteClosingFee -> {
+                                logger.info { "c:$channelId they accepted our fee, publishing closing tx: closingTxId=${signedClosingTx.tx.txid}" }
+                                completeMutualClose(signedClosingTx, null)
+                            }
+                            closingTxProposed.flatten().size >= MAX_NEGOTIATION_ITERATIONS -> {
+                                logger.warning { "c:$channelId could not agree on closing fees after $MAX_NEGOTIATION_ITERATIONS iterations, publishing closing tx: closingTxId=${signedClosingTx.tx.txid}" }
+                                completeMutualClose(signedClosingTx, closingSignedRemoteFees)
+                            }
+                            lastLocalClosingSigned?.tlvStream?.get<ClosingSignedTlv.FeeRange>()?.let { it.min <= remoteClosingFee && remoteClosingFee <= it.max } == true -> {
+                                val localFeeRange = lastLocalClosingSigned.tlvStream.get<ClosingSignedTlv.FeeRange>()!!
+                                logger.info { "c:$channelId they chose closing fee=$remoteClosingFee within our fee range (min=${localFeeRange.max} max=${localFeeRange.max}), publishing closing tx: closingTxId=${signedClosingTx.tx.txid}" }
+                                completeMutualClose(signedClosingTx, closingSignedRemoteFees)
+                            }
+                            commitments.localCommit.spec.toLocal == 0.msat -> {
+                                logger.info { "c:$channelId we have nothing at stake, publishing closing tx: closingTxId=${signedClosingTx.tx.txid}" }
+                                completeMutualClose(signedClosingTx, closingSignedRemoteFees)
+                            }
+                            else -> {
+                                val theirFeeRange = event.message.tlvStream.get<ClosingSignedTlv.FeeRange>()
+                                val ourFeeRange = closingFeerates ?: ClosingFeerates(currentOnChainFeerates.mutualCloseFeerate)
+                                when {
+                                    theirFeeRange != null && !commitments.localParams.isFunder -> {
+                                        // if we are fundee and they proposed a fee range, we pick a value in that range and they should accept it without further negotiation
+                                        // we don't care much about the closing fee since they're paying it (not us) and we can use CPFP if we want to speed up confirmation
+                                        val closingFees = Helpers.Closing.firstClosingFee(commitments, localShutdown.scriptPubKey, remoteShutdown.scriptPubKey, ourFeeRange)
+                                        val closingFee = when {
+                                            closingFees.preferred > theirFeeRange.max -> theirFeeRange.max
+                                            // if we underestimate the fee, then we're happy with whatever they propose (it will confirm more quickly and we're not paying it)
+                                            closingFees.preferred < remoteClosingFee -> remoteClosingFee
+                                            else -> closingFees.preferred
+                                        }
+                                        if (closingFee == remoteClosingFee) {
+                                            logger.info { "c:$channelId accepting their closing fee=$remoteClosingFee, publishing closing tx: closingTxId=${signedClosingTx.tx.txid}" }
+                                            completeMutualClose(signedClosingTx, closingSignedRemoteFees)
+                                        } else {
+                                            val (closingTx, closingSigned) = Helpers.Closing.makeClosingTx(
+                                                keyManager,
+                                                commitments,
+                                                localShutdown.scriptPubKey.toByteArray(),
+                                                remoteShutdown.scriptPubKey.toByteArray(),
+                                                ClosingFees(closingFee, theirFeeRange.min, theirFeeRange.max)
+                                            )
+                                            logger.info { "c:$channelId proposing closing fee=${closingSigned.feeSatoshis}" }
+                                            val closingProposed1 = closingTxProposed.updated(
+                                                closingTxProposed.lastIndex,
+                                                closingTxProposed.last() + listOf(ClosingTxProposed(closingTx, closingSigned))
+                                            )
+                                            val nextState = this.copy(
+                                                commitments = commitments.copy(remoteChannelData = event.message.channelData),
+                                                closingTxProposed = closingProposed1,
+                                                bestUnpublishedClosingTx = signedClosingTx
+                                            )
+                                            val actions = listOf(ChannelAction.Storage.StoreState(nextState), ChannelAction.Message.Send(closingSigned))
+                                            Pair(nextState, actions)
+                                        }
+                                    }
+                                    else -> {
+                                        val (closingTx, closingSigned) = run {
+                                            // if we are fundee and we were waiting for them to send their first closing_signed, we compute our firstClosingFee, otherwise we use the last one we sent
+                                            val localClosingFees = Helpers.Closing.firstClosingFee(commitments, localShutdown.scriptPubKey, remoteShutdown.scriptPubKey, ourFeeRange)
+                                            val nextPreferredFee = Helpers.Closing.nextClosingFee(lastLocalClosingSigned?.feeSatoshis ?: localClosingFees.preferred, remoteClosingFee)
+                                            Helpers.Closing.makeClosingTx(keyManager, commitments, localShutdown.scriptPubKey.toByteArray(), remoteShutdown.scriptPubKey.toByteArray(), localClosingFees.copy(preferred = nextPreferredFee))
+                                        }
+                                        when {
+                                            lastLocalClosingSigned?.feeSatoshis == closingSigned.feeSatoshis -> {
+                                                // next computed fee is the same than the one we previously sent (probably because of rounding)
+                                                logger.info { "c:$channelId accepting their closing fee=$remoteClosingFee, publishing closing tx: closingTxId=${signedClosingTx.tx.txid}" }
+                                                completeMutualClose(signedClosingTx, null)
+                                            }
+                                            closingSigned.feeSatoshis == remoteClosingFee -> {
+                                                logger.info { "c:$channelId we have converged, publishing closing tx: closingTxId=${signedClosingTx.tx.txid}" }
+                                                completeMutualClose(signedClosingTx, closingSigned)
+                                            }
+                                            else -> {
+                                                logger.info { "c:$channelId proposing closing fee=${closingSigned.feeSatoshis}" }
+                                                val closingProposed1 = closingTxProposed.updated(
+                                                    closingTxProposed.lastIndex,
+                                                    closingTxProposed.last() + listOf(ClosingTxProposed(closingTx, closingSigned))
+                                                )
+                                                val nextState = this.copy(
+                                                    commitments = commitments.copy(remoteChannelData = event.message.channelData),
+                                                    closingTxProposed = closingProposed1,
+                                                    bestUnpublishedClosingTx = signedClosingTx
+                                                )
+                                                val actions = listOf(ChannelAction.Storage.StoreState(nextState), ChannelAction.Message.Send(closingSigned))
+                                                Pair(nextState, actions)
+                                            }
+                                        }
+                                    }
+                                }
+                            }
                         }
                     }
                 }
-                when (result) {
-                    is Either.Right -> result.value
-                    is Either.Left -> handleLocalError(event, result.value)
-                }
             }
             event is ChannelEvent.MessageReceived && event.message is Error -> handleRemoteError(event.message)
             event is ChannelEvent.WatchReceived -> when (val watch = event.watch) {
@@ -2486,6 +2519,26 @@ data class Negotiating(
         return closingTxProposed.flatten().first { it.unsignedTx.tx.txid == tx.txid }.unsignedTx.copy(tx = tx)
     }
 
+    private fun completeMutualClose(signedClosingTx: ClosingTx, closingSigned: ClosingSigned?): Pair<ChannelState, List<ChannelAction>> {
+        val nextState = Closing(
+            staticParams,
+            currentTip,
+            currentOnChainFeerates,
+            commitments,
+            fundingTx = null,
+            waitingSinceBlock = currentBlockHeight.toLong(),
+            mutualCloseProposed = closingTxProposed.flatten().map { it.unsignedTx },
+            mutualClosePublished = listOf(signedClosingTx)
+        )
+        val actions = buildList {
+            add(ChannelAction.Storage.StoreState(nextState))
+            closingSigned?.let { add(ChannelAction.Message.Send(it)) }
+            add(ChannelAction.Blockchain.PublishTx(signedClosingTx.tx))
+            add(ChannelAction.Blockchain.SendWatch(WatchConfirmed(channelId, signedClosingTx.tx, staticParams.nodeParams.minDepthBlocks.toLong(), BITCOIN_TX_CONFIRMED(signedClosingTx.tx))))
+        }
+        return Pair(nextState, actions)
+    }
+
     override fun handleLocalError(event: ChannelEvent, t: Throwable): Pair<ChannelState, List<ChannelAction>> {
         logger.error(t) { "c:$channelId error on event ${event::class} in state ${this::class}" }
         val error = Error(channelId, t.message)
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/channel/ChannelCommands.kt b/src/commonMain/kotlin/fr/acinq/lightning/channel/ChannelCommands.kt
index 7e6cce837..53491ce96 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/channel/ChannelCommands.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/channel/ChannelCommands.kt
@@ -2,9 +2,11 @@ package fr.acinq.lightning.channel
 
 import fr.acinq.bitcoin.ByteVector
 import fr.acinq.bitcoin.ByteVector32
+import fr.acinq.bitcoin.Satoshi
 import fr.acinq.lightning.CltvExpiry
 import fr.acinq.lightning.MilliSatoshi
 import fr.acinq.lightning.blockchain.fee.FeeratePerKw
+import fr.acinq.lightning.transactions.Transactions.weight2fee
 import fr.acinq.lightning.utils.UUID
 import fr.acinq.lightning.wire.FailureMessage
 import fr.acinq.lightning.wire.OnionRoutingPacket
@@ -29,6 +31,16 @@ data class CMD_FAIL_HTLC(override val id: Long, val reason: Reason, val commit:
 object CMD_SIGN : Command()
 data class CMD_UPDATE_FEE(val feerate: FeeratePerKw, val commit: Boolean = false) : Command()
 
+data class ClosingFees(val preferred: Satoshi, val min: Satoshi, val max: Satoshi) {
+    constructor(preferred: Satoshi) : this(preferred, preferred, preferred)
+}
+
+data class ClosingFeerates(val preferred: FeeratePerKw, val min: FeeratePerKw, val max: FeeratePerKw) {
+    constructor(preferred: FeeratePerKw) : this(preferred, preferred / 2, preferred * 2)
+
+    fun computeFees(closingTxWeight: Int): ClosingFees = ClosingFees(weight2fee(preferred, closingTxWeight), weight2fee(min, closingTxWeight), weight2fee(max, closingTxWeight))
+}
+
 sealed class CloseCommand : Command()
-data class CMD_CLOSE(val scriptPubKey: ByteVector?) : CloseCommand()
+data class CMD_CLOSE(val scriptPubKey: ByteVector?, val feerates: ClosingFeerates?) : CloseCommand()
 object CMD_FORCECLOSE : CloseCommand()
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/channel/Helpers.kt b/src/commonMain/kotlin/fr/acinq/lightning/channel/Helpers.kt
index 11222403d..6af11e2e7 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/channel/Helpers.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/channel/Helpers.kt
@@ -441,14 +441,14 @@ object Helpers {
             }.getOrElse { null }
         }
 
-        fun firstClosingFee(commitments: Commitments, localScriptPubkey: ByteArray, remoteScriptPubkey: ByteArray, requestedFeerate: FeeratePerKw): Satoshi {
+        fun firstClosingFee(commitments: Commitments, localScriptPubkey: ByteArray, remoteScriptPubkey: ByteArray, requestedFeerate: ClosingFeerates): ClosingFees {
             // this is just to estimate the weight which depends on the size of the pubkey scripts
             val dummyClosingTx = Transactions.makeClosingTx(commitments.commitInput, localScriptPubkey, remoteScriptPubkey, commitments.localParams.isFunder, Satoshi(0), Satoshi(0), commitments.localCommit.spec)
             val closingWeight = Transaction.weight(Transactions.addSigs(dummyClosingTx, dummyPublicKey, commitments.remoteParams.fundingPubKey, Transactions.PlaceHolderSig, Transactions.PlaceHolderSig).tx)
-            return Transactions.weight2fee(requestedFeerate, closingWeight)
+            return requestedFeerate.computeFees(closingWeight)
         }
 
-        fun firstClosingFee(commitments: Commitments, localScriptPubkey: ByteVector, remoteScriptPubkey: ByteVector, requestedFeerate: FeeratePerKw): Satoshi =
+        fun firstClosingFee(commitments: Commitments, localScriptPubkey: ByteVector, remoteScriptPubkey: ByteVector, requestedFeerate: ClosingFeerates): ClosingFees =
             firstClosingFee(commitments, localScriptPubkey.toByteArray(), remoteScriptPubkey.toByteArray(), requestedFeerate)
 
         fun nextClosingFee(localClosingFee: Satoshi, remoteClosingFee: Satoshi): Satoshi = ((localClosingFee + remoteClosingFee) / 4) * 2
@@ -458,10 +458,10 @@ object Helpers {
             commitments: Commitments,
             localScriptPubkey: ByteArray,
             remoteScriptPubkey: ByteArray,
-            requestedFeerate: FeeratePerKw
-        ): Pair<Transactions.TransactionWithInputInfo.ClosingTx, ClosingSigned> {
-            val closingFee = firstClosingFee(commitments, localScriptPubkey, remoteScriptPubkey, requestedFeerate)
-            return makeClosingTx(keyManager, commitments, localScriptPubkey, remoteScriptPubkey, closingFee)
+            requestedFeerate: ClosingFeerates
+        ): Pair<ClosingTx, ClosingSigned> {
+            val closingFees = firstClosingFee(commitments, localScriptPubkey, remoteScriptPubkey, requestedFeerate)
+            return makeClosingTx(keyManager, commitments, localScriptPubkey, remoteScriptPubkey, closingFees)
         }
 
         fun makeClosingTx(
@@ -469,14 +469,14 @@ object Helpers {
             commitments: Commitments,
             localScriptPubkey: ByteArray,
             remoteScriptPubkey: ByteArray,
-            closingFee: Satoshi
-        ): Pair<Transactions.TransactionWithInputInfo.ClosingTx, ClosingSigned> {
+            closingFees: ClosingFees
+        ): Pair<ClosingTx, ClosingSigned> {
             require(isValidFinalScriptPubkey(localScriptPubkey)) { "invalid localScriptPubkey" }
             require(isValidFinalScriptPubkey(remoteScriptPubkey)) { "invalid remoteScriptPubkey" }
             val dustLimit = commitments.localParams.dustLimit.max(commitments.remoteParams.dustLimit)
-            val closingTx = Transactions.makeClosingTx(commitments.commitInput, localScriptPubkey, remoteScriptPubkey, commitments.localParams.isFunder, dustLimit, closingFee, commitments.localCommit.spec)
+            val closingTx = Transactions.makeClosingTx(commitments.commitInput, localScriptPubkey, remoteScriptPubkey, commitments.localParams.isFunder, dustLimit, closingFees.preferred, commitments.localCommit.spec)
             val localClosingSig = keyManager.sign(closingTx, commitments.localParams.channelKeys.fundingPrivateKey)
-            val closingSigned = ClosingSigned(commitments.channelId, closingFee, localClosingSig)
+            val closingSigned = ClosingSigned(commitments.channelId, closingFees.preferred, localClosingSig, TlvStream(listOf(ClosingSignedTlv.FeeRange(closingFees.min, closingFees.max))))
             return Pair(closingTx, closingSigned)
         }
 
@@ -487,11 +487,11 @@ object Helpers {
             remoteScriptPubkey: ByteArray,
             remoteClosingFee: Satoshi,
             remoteClosingSig: ByteVector64
-        ): Either<ChannelException, ClosingTx> {
-            val (closingTx, closingSigned) = makeClosingTx(keyManager, commitments, localScriptPubkey, remoteScriptPubkey, remoteClosingFee)
+        ): Either<ChannelException, Pair<ClosingTx, ClosingSigned>> {
+            val (closingTx, closingSigned) = makeClosingTx(keyManager, commitments, localScriptPubkey, remoteScriptPubkey, ClosingFees(remoteClosingFee))
             val signedClosingTx = Transactions.addSigs(closingTx, commitments.localParams.channelKeys.fundingPubKey, commitments.remoteParams.fundingPubKey, closingSigned.signature, remoteClosingSig)
             return when (Transactions.checkSpendable(signedClosingTx)) {
-                is Try.Success -> Either.Right(signedClosingTx)
+                is Try.Success -> Either.Right(Pair(signedClosingTx, closingSigned))
                 is Try.Failure -> Either.Left(InvalidCloseSignature(commitments.channelId, signedClosingTx.tx))
             }
         }
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/serialization/v1/ChannelState.kt b/src/commonMain/kotlin/fr/acinq/lightning/serialization/v1/ChannelState.kt
index 3766588ad..1bbaf692a 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/serialization/v1/ChannelState.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/serialization/v1/ChannelState.kt
@@ -731,7 +731,8 @@ data class Normal(
         channelUpdate,
         remoteChannelUpdate,
         localShutdown,
-        remoteShutdown
+        remoteShutdown,
+        null
     )
 }
 
@@ -759,7 +760,8 @@ data class ShuttingDown(
         currentOnChainFeerates.export(),
         commitments.export(nodeParams),
         localShutdown,
-        remoteShutdown
+        remoteShutdown,
+        null
     )
 }
 
@@ -798,7 +800,8 @@ data class Negotiating(
         localShutdown,
         remoteShutdown,
         closingTxProposed.map { x -> x.map { it.export() } },
-        bestUnpublishedClosingTx
+        bestUnpublishedClosingTx,
+        null
     )
 }
 
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/serialization/v2/ChannelState.kt b/src/commonMain/kotlin/fr/acinq/lightning/serialization/v2/ChannelState.kt
index f8bf4b9fb..1e21796d3 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/serialization/v2/ChannelState.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/serialization/v2/ChannelState.kt
@@ -724,7 +724,8 @@ data class Normal(
         channelUpdate,
         remoteChannelUpdate,
         localShutdown,
-        remoteShutdown
+        remoteShutdown,
+        null
     )
 }
 
@@ -752,7 +753,8 @@ data class ShuttingDown(
         currentOnChainFeerates.export(),
         commitments.export(nodeParams),
         localShutdown,
-        remoteShutdown
+        remoteShutdown,
+        null
     )
 }
 
@@ -791,7 +793,8 @@ data class Negotiating(
         localShutdown,
         remoteShutdown,
         closingTxProposed.map { x -> x.map { it.export() } },
-        bestUnpublishedClosingTx
+        bestUnpublishedClosingTx,
+        null
     )
 }
 
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/serialization/v3/ChannelState.kt b/src/commonMain/kotlin/fr/acinq/lightning/serialization/v3/ChannelState.kt
index 0183797b4..079837702 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/serialization/v3/ChannelState.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/serialization/v3/ChannelState.kt
@@ -272,6 +272,13 @@ data class ChannelFeatures(@Serializable(with = ByteVectorKSerializer::class) va
     fun export() = fr.acinq.lightning.channel.ChannelFeatures(Features(bin.toByteArray()).activated.keys)
 }
 
+@Serializable
+data class ClosingFeerates(val preferred: FeeratePerKw, val min: FeeratePerKw, val max: FeeratePerKw) {
+    constructor(from: fr.acinq.lightning.channel.ClosingFeerates) : this(from.preferred, from.min, from.max)
+
+    fun export() = fr.acinq.lightning.channel.ClosingFeerates(preferred, min, max)
+}
+
 @Serializable
 data class ClosingTxProposed(val unsignedTx: Transactions.TransactionWithInputInfo.ClosingTx, val localClosingSigned: ClosingSigned) {
     constructor(from: fr.acinq.lightning.channel.ClosingTxProposed) : this(from.unsignedTx, from.localClosingSigned)
@@ -701,7 +708,8 @@ data class Normal(
     val channelUpdate: ChannelUpdate,
     val remoteChannelUpdate: ChannelUpdate?,
     val localShutdown: Shutdown?,
-    val remoteShutdown: Shutdown?
+    val remoteShutdown: Shutdown?,
+    val closingFeerates: ClosingFeerates?
 ) : ChannelStateWithCommitments() {
     constructor(from: fr.acinq.lightning.channel.Normal) : this(
         StaticParams(from.staticParams),
@@ -714,7 +722,8 @@ data class Normal(
         from.channelUpdate,
         from.remoteChannelUpdate,
         from.localShutdown,
-        from.remoteShutdown
+        from.remoteShutdown,
+        from.closingFeerates?.let { ClosingFeerates(it) }
     )
 
     override fun export(nodeParams: NodeParams) = fr.acinq.lightning.channel.Normal(
@@ -728,7 +737,8 @@ data class Normal(
         channelUpdate,
         remoteChannelUpdate,
         localShutdown,
-        remoteShutdown
+        remoteShutdown,
+        closingFeerates?.export()
     )
 }
 
@@ -739,7 +749,8 @@ data class ShuttingDown(
     override val currentOnChainFeerates: OnChainFeerates,
     override val commitments: Commitments,
     val localShutdown: Shutdown,
-    val remoteShutdown: Shutdown
+    val remoteShutdown: Shutdown,
+    val closingFeerates: ClosingFeerates?
 ) : ChannelStateWithCommitments() {
     constructor(from: fr.acinq.lightning.channel.ShuttingDown) : this(
         StaticParams(from.staticParams),
@@ -747,7 +758,8 @@ data class ShuttingDown(
         OnChainFeerates(from.currentOnChainFeerates),
         Commitments(from.commitments),
         from.localShutdown,
-        from.remoteShutdown
+        from.remoteShutdown,
+        from.closingFeerates?.let { ClosingFeerates(it) }
     )
 
     override fun export(nodeParams: NodeParams) = fr.acinq.lightning.channel.ShuttingDown(
@@ -756,7 +768,8 @@ data class ShuttingDown(
         currentOnChainFeerates.export(),
         commitments.export(nodeParams),
         localShutdown,
-        remoteShutdown
+        remoteShutdown,
+        closingFeerates?.export()
     )
 }
 
@@ -769,7 +782,8 @@ data class Negotiating(
     val localShutdown: Shutdown,
     val remoteShutdown: Shutdown,
     val closingTxProposed: List<List<ClosingTxProposed>>,
-    val bestUnpublishedClosingTx: Transactions.TransactionWithInputInfo.ClosingTx?
+    val bestUnpublishedClosingTx: Transactions.TransactionWithInputInfo.ClosingTx?,
+    val closingFeerates: ClosingFeerates?
 ) : ChannelStateWithCommitments() {
     init {
         require(closingTxProposed.isNotEmpty()) { "there must always be a list for the current negotiation" }
@@ -784,7 +798,8 @@ data class Negotiating(
         from.localShutdown,
         from.remoteShutdown,
         from.closingTxProposed.map { x -> x.map { ClosingTxProposed(it) } },
-        from.bestUnpublishedClosingTx
+        from.bestUnpublishedClosingTx,
+        from.closingFeerates?.let { ClosingFeerates(it) }
     )
 
     override fun export(nodeParams: NodeParams) = fr.acinq.lightning.channel.Negotiating(
@@ -795,7 +810,8 @@ data class Negotiating(
         localShutdown,
         remoteShutdown,
         closingTxProposed.map { x -> x.map { it.export() } },
-        bestUnpublishedClosingTx
+        bestUnpublishedClosingTx,
+        closingFeerates?.export()
     )
 }
 
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/wire/ChannelTlv.kt b/src/commonMain/kotlin/fr/acinq/lightning/wire/ChannelTlv.kt
index 2bef63306..431cee924 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/wire/ChannelTlv.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/wire/ChannelTlv.kt
@@ -219,6 +219,21 @@ sealed class ShutdownTlv : Tlv {
 
 @Serializable
 sealed class ClosingSignedTlv : Tlv {
+    @Serializable
+    data class FeeRange(@Contextual val min: Satoshi, @Contextual val max: Satoshi) : ClosingSignedTlv() {
+        override val tag: Long get() = FeeRange.tag
+
+        override fun write(out: Output) {
+            LightningCodecs.writeU64(min.toLong(), out)
+            LightningCodecs.writeU64(max.toLong(), out)
+        }
+
+        companion object : TlvValueReader<FeeRange> {
+            const val tag: Long = 1
+            override fun read(input: Input): FeeRange = FeeRange(Satoshi(LightningCodecs.u64(input)), Satoshi(LightningCodecs.u64(input)))
+        }
+    }
+
     @Serializable
     data class ChannelData(@Contextual val ecb: EncryptedChannelData) : ClosingSignedTlv() {
         override val tag: Long get() = ChannelData.tag
diff --git a/src/commonMain/kotlin/fr/acinq/lightning/wire/LightningMessages.kt b/src/commonMain/kotlin/fr/acinq/lightning/wire/LightningMessages.kt
index bd67a96ba..dc275ca7b 100644
--- a/src/commonMain/kotlin/fr/acinq/lightning/wire/LightningMessages.kt
+++ b/src/commonMain/kotlin/fr/acinq/lightning/wire/LightningMessages.kt
@@ -1048,7 +1048,10 @@ data class ClosingSigned(
         const val type: Long = 39
 
         @Suppress("UNCHECKED_CAST")
-        val readers = mapOf(ClosingSignedTlv.ChannelData.tag to ClosingSignedTlv.ChannelData.Companion as TlvValueReader<ClosingSignedTlv>)
+        val readers = mapOf(
+            ClosingSignedTlv.FeeRange.tag to ClosingSignedTlv.FeeRange.Companion as TlvValueReader<ClosingSignedTlv>,
+            ClosingSignedTlv.ChannelData.tag to ClosingSignedTlv.ChannelData.Companion as TlvValueReader<ClosingSignedTlv>
+        )
 
         override fun read(input: Input): ClosingSigned {
             return ClosingSigned(
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/TestsHelper.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/TestsHelper.kt
index 1441267e1..4c61d1060 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/TestsHelper.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/TestsHelper.kt
@@ -180,32 +180,38 @@ object TestsHelper {
         return Pair(alice as Normal, bob as Normal)
     }
 
-    fun mutualClose(
-        alice: Normal,
-        bob: Normal,
-        tweakFees: Boolean = false,
-        scriptPubKey: ByteVector? = null
-    ): Triple<Negotiating, Negotiating, ClosingSigned> {
-        val alice1 = alice.updateFeerate(if (tweakFees) FeeratePerKw(4_319.sat) else FeeratePerKw(10_000.sat))
-        val bob1 = bob.updateFeerate(if (tweakFees) FeeratePerKw(4_319.sat) else FeeratePerKw(10_000.sat))
-
-        // Bob is fundee and initiates the closing
-        val (bob2, actions) = bob1.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(scriptPubKey)))
-        assertTrue(bob2 is Normal)
-        val shutdown = actions.findOutgoingMessage<Shutdown>()
-
-        // Alice is funder, she will sign the first closing tx
-        val (alice2, actions1) = alice1.process(ChannelEvent.MessageReceived(shutdown))
+    fun mutualCloseAlice(alice: Normal, bob: Normal, scriptPubKey: ByteVector? = null, feerates: ClosingFeerates? = null): Triple<Negotiating, Negotiating, ClosingSigned> {
+        val (alice1, actionsAlice1) = alice.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(scriptPubKey, feerates)))
+        assertTrue(alice1 is Normal)
+        val shutdownAlice = actionsAlice1.findOutgoingMessage<Shutdown>()
+        assertNull(actionsAlice1.findOutgoingMessageOpt<ClosingSigned>())
+
+        val (bob1, actionsBob1) = bob.process(ChannelEvent.MessageReceived(shutdownAlice))
+        assertTrue(bob1 is Negotiating)
+        val shutdownBob = actionsBob1.findOutgoingMessage<Shutdown>()
+        assertNull(actionsBob1.findOutgoingMessageOpt<ClosingSigned>())
+
+        val (alice2, actionsAlice2) = alice1.process(ChannelEvent.MessageReceived(shutdownBob))
         assertTrue(alice2 is Negotiating)
-        val shutdown1 = actions1.findOutgoingMessage<Shutdown>()
-        val closingSigned = actions1.findOutgoingMessage<ClosingSigned>()
-
-        val alice3 = alice2.updateFeerate(if (tweakFees) FeeratePerKw(4_316.sat) else FeeratePerKw(5_000.sat))
-        val bob3 = bob2.updateFeerate(if (tweakFees) FeeratePerKw(4_316.sat) else FeeratePerKw(5_000.sat))
+        val closingSignedAlice = actionsAlice2.findOutgoingMessage<ClosingSigned>()
+        return Triple(alice2, bob1, closingSignedAlice)
+    }
 
-        val (bob4, _) = bob3.process(ChannelEvent.MessageReceived(shutdown1))
-        assertTrue(bob4 is Negotiating)
-        return Triple(alice3, bob4, closingSigned)
+    fun mutualCloseBob(alice: Normal, bob: Normal, scriptPubKey: ByteVector? = null, feerates: ClosingFeerates? = null): Triple<Negotiating, Negotiating, ClosingSigned> {
+        val (bob1, actionsBob1) = bob.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(scriptPubKey, feerates)))
+        assertTrue(bob1 is Normal)
+        val shutdownBob = actionsBob1.findOutgoingMessage<Shutdown>()
+        assertNull(actionsBob1.findOutgoingMessageOpt<ClosingSigned>())
+
+        val (alice1, actionsAlice1) = alice.process(ChannelEvent.MessageReceived(shutdownBob))
+        assertTrue(alice1 is Negotiating)
+        val shutdownAlice = actionsAlice1.findOutgoingMessage<Shutdown>()
+        val closingSignedAlice = actionsAlice1.findOutgoingMessage<ClosingSigned>()
+
+        val (bob2, actionsBob2) = bob1.process(ChannelEvent.MessageReceived(shutdownAlice))
+        assertTrue(bob2 is Negotiating)
+        assertNull(actionsBob2.findOutgoingMessageOpt<ClosingSigned>())
+        return Triple(alice1, bob2, closingSignedAlice)
     }
 
     fun localClose(s: ChannelState): Pair<Closing, LocalCommitPublished> {
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ClosingTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ClosingTestsCommon.kt
index 48d6a8528..8d4af60d2 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ClosingTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ClosingTestsCommon.kt
@@ -19,7 +19,8 @@ import fr.acinq.lightning.channel.TestsHelper.htlcSuccessTxs
 import fr.acinq.lightning.channel.TestsHelper.htlcTimeoutTxs
 import fr.acinq.lightning.channel.TestsHelper.localClose
 import fr.acinq.lightning.channel.TestsHelper.makeCmdAdd
-import fr.acinq.lightning.channel.TestsHelper.mutualClose
+import fr.acinq.lightning.channel.TestsHelper.mutualCloseAlice
+import fr.acinq.lightning.channel.TestsHelper.mutualCloseBob
 import fr.acinq.lightning.channel.TestsHelper.processEx
 import fr.acinq.lightning.channel.TestsHelper.reachNormal
 import fr.acinq.lightning.channel.TestsHelper.remoteClose
@@ -34,24 +35,6 @@ import kotlin.test.*
 
 class ClosingTestsCommon : LightningTestSuite() {
 
-    @Test
-    fun `start fee negotiation from configured block target`() {
-        val (alice, bob) = reachNormal()
-        val (alice1, actions) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
-        val shutdown = actions.findOutgoingMessage<Shutdown>()
-        val (_, actions1) = bob.processEx(ChannelEvent.MessageReceived(shutdown))
-        val shutdown1 = actions1.findOutgoingMessage<Shutdown>()
-        val (alice2, actions2) = alice1.processEx(ChannelEvent.MessageReceived(shutdown1))
-        val closingSigned = actions2.findOutgoingMessage<ClosingSigned>()
-        val expectedProposedFee = Helpers.Closing.firstClosingFee(
-            (alice2 as Negotiating).commitments,
-            alice2.localShutdown.scriptPubKey.toByteArray(),
-            alice2.remoteShutdown.scriptPubKey.toByteArray(),
-            alice2.currentOnChainFeerates.mutualCloseFeerate
-        )
-        assertEquals(closingSigned.feeSatoshis, expectedProposedFee)
-    }
-
     @Test
     fun `recv CMD_ADD_HTLC`() {
         val (alice, _, _) = initMutualClose()
@@ -80,43 +63,39 @@ class ClosingTestsCommon : LightningTestSuite() {
     @Test
     fun `recv BITCOIN_FUNDING_SPENT (mutual close before converging)`() {
         val (alice0, bob0) = reachNormal()
-        // alice initiates a closing
-        val (alice1, aliceActions1) = alice0.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        // alice initiates a closing with a low fee
+        val (alice1, aliceActions1) = alice0.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, ClosingFeerates(FeeratePerKw(500.sat), FeeratePerKw(250.sat), FeeratePerKw(1000.sat)))))
         val shutdown0 = aliceActions1.findOutgoingMessage<Shutdown>()
         val (bob1, bobActions1) = bob0.processEx(ChannelEvent.MessageReceived(shutdown0))
+        assertTrue(bob1 is Negotiating)
         val shutdown1 = bobActions1.findOutgoingMessage<Shutdown>()
-        val (alice2, aliceActions2) = alice1.processEx(ChannelEvent.MessageReceived(shutdown1))
-
-        // agreeing on a closing fee
+        val (alice2, aliceActions2) = alice1.process(ChannelEvent.MessageReceived(shutdown1))
+        assertTrue(alice2 is Negotiating)
         val closingSigned0 = aliceActions2.findOutgoingMessage<ClosingSigned>()
-        val aliceCloseFee = closingSigned0.feeSatoshis
-        val bob2 = (bob1 as Negotiating).updateFeerate(FeeratePerKw(5_000.sat))
-        val (_, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(closingSigned0))
-        val closingSigned1 = bobActions3.findOutgoingMessage<ClosingSigned>()
-        val bobCloseFee = closingSigned1.feeSatoshis
-        val (alice3, _) = alice2.processEx(ChannelEvent.MessageReceived(closingSigned1))
-
-        // they don't converge yet, but alice has a publishable commit tx now
-        assertNotEquals(aliceCloseFee, bobCloseFee)
-        val mutualCloseTx = (alice3 as Negotiating).bestUnpublishedClosingTx
+
+        // they don't converge yet, but bob has a publishable commit tx now
+        val (bob2, bobActions2) = bob1.processEx(ChannelEvent.MessageReceived(closingSigned0))
+        assertTrue(bob2 is Negotiating)
+        val mutualCloseTx = bob2.bestUnpublishedClosingTx
         assertNotNull(mutualCloseTx)
+        val closingSigned1 = bobActions2.findOutgoingMessage<ClosingSigned>()
+        assertNotEquals(closingSigned0.feeSatoshis, closingSigned1.feeSatoshis)
 
-        // let's make alice publish this closing tx
-        val (alice4, aliceActions4) = alice3.processEx(ChannelEvent.MessageReceived(Error(ByteVector32.Zeroes, "")))
-        assertTrue { alice4 is Closing }
-        assertEquals(ChannelAction.Blockchain.PublishTx(mutualCloseTx.tx), aliceActions4.filterIsInstance<ChannelAction.Blockchain.PublishTx>().first())
-        assertEquals(mutualCloseTx, (alice4 as Closing).mutualClosePublished.last())
-        aliceActions4.has<ChannelAction.Storage.StoreChannelClosing>()
+        // let's make bob publish this closing tx
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(Error(ByteVector32.Zeroes, "")))
+        assertTrue(bob3 is Closing)
+        assertEquals(ChannelAction.Blockchain.PublishTx(mutualCloseTx.tx), bobActions3.filterIsInstance<ChannelAction.Blockchain.PublishTx>().first())
+        assertEquals(mutualCloseTx, bob3.mutualClosePublished.last())
+        bobActions3.has<ChannelAction.Storage.StoreChannelClosing>()
 
         // actual test starts here
-        val (alice5, _) = alice4.processEx(ChannelEvent.WatchReceived(WatchEventSpent(ByteVector32.Zeroes, BITCOIN_FUNDING_SPENT, mutualCloseTx.tx)))
-        val (alice6, aliceActions6) = alice5.processEx(ChannelEvent.WatchReceived(WatchEventConfirmed(ByteVector32.Zeroes, BITCOIN_TX_CONFIRMED(mutualCloseTx.tx), 0, 0, mutualCloseTx.tx)))
-
-        assertTrue { alice6 is Closed }
-        val storeChannelClosed = aliceActions6.filterIsInstance<ChannelAction.Storage.StoreChannelClosed>().firstOrNull()
+        val (bob4, _) = bob3.processEx(ChannelEvent.WatchReceived(WatchEventSpent(ByteVector32.Zeroes, BITCOIN_FUNDING_SPENT, mutualCloseTx.tx)))
+        val (bob5, bobActions5) = bob4.processEx(ChannelEvent.WatchReceived(WatchEventConfirmed(ByteVector32.Zeroes, BITCOIN_TX_CONFIRMED(mutualCloseTx.tx), 0, 0, mutualCloseTx.tx)))
+        assertTrue(bob5 is Closed)
+        val storeChannelClosed = bobActions5.filterIsInstance<ChannelAction.Storage.StoreChannelClosed>().firstOrNull()
         assertNotNull(storeChannelClosed)
-        assertTrue { storeChannelClosed.closingType == ChannelClosingType.Mutual }
-        assertTrue { storeChannelClosed.txids == listOf(mutualCloseTx.tx.txid) }
+        assertEquals(storeChannelClosed.closingType, ChannelClosingType.Mutual)
+        assertEquals(storeChannelClosed.txids, listOf(mutualCloseTx.tx.txid))
     }
 
     @Test
@@ -126,11 +105,11 @@ class ClosingTestsCommon : LightningTestSuite() {
 
         // actual test starts here
         val (alice1, actions1) = alice0.processEx(ChannelEvent.WatchReceived(WatchEventConfirmed(ByteVector32.Zeroes, BITCOIN_TX_CONFIRMED(mutualCloseTx.tx), 0, 0, mutualCloseTx.tx)))
-        assertTrue { alice1 is Closed }
+        assertTrue(alice1 is Closed)
         val storeChannelClosed = actions1.filterIsInstance<ChannelAction.Storage.StoreChannelClosed>().firstOrNull()
         assertNotNull(storeChannelClosed)
-        assertTrue { storeChannelClosed.closingType == ChannelClosingType.Mutual }
-        assertTrue { storeChannelClosed.txids == listOf(mutualCloseTx.tx.txid) }
+        assertEquals(storeChannelClosed.closingType, ChannelClosingType.Mutual)
+        assertEquals(storeChannelClosed.txids, listOf(mutualCloseTx.tx.txid))
     }
 
     @Test
@@ -140,23 +119,16 @@ class ClosingTestsCommon : LightningTestSuite() {
         val bobFinalScript = Script.write(Script.pay2pkh(pubKey)).toByteVector()
 
         val (alice1, bob1) = reachNormal()
-        val (alice2, bob2, aliceClosingSigned1) = mutualClose(alice1, bob1, tweakFees = true, scriptPubKey = bobFinalScript)
+        val (_, bob2, aliceClosingSigned) = mutualCloseBob(alice1, bob1, scriptPubKey = bobFinalScript)
 
-        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceClosingSigned1))
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceClosingSigned))
+        assertTrue(bob3 is Closing)
         val bobClosingSigned = bobActions3.findOutgoingMessageOpt<ClosingSigned>()
         assertNotNull(bobClosingSigned)
-
-        val (alice4, aliceActions4) = alice2.processEx(ChannelEvent.MessageReceived(bobClosingSigned))
-        assertTrue { alice4 is Closing }
-        val aliceClosingSigned2 = aliceActions4.findOutgoingMessageOpt<ClosingSigned>()
-        assertNotNull(aliceClosingSigned2)
-
-        val (bob5, bobActions5) = bob3.processEx(ChannelEvent.MessageReceived(aliceClosingSigned2))
-        assertTrue { bob5 is Closing }
-        val storeChannelClosing = bobActions5.filterIsInstance<ChannelAction.Storage.StoreChannelClosing>().firstOrNull()
+        val storeChannelClosing = bobActions3.filterIsInstance<ChannelAction.Storage.StoreChannelClosing>().firstOrNull()
         assertNotNull(storeChannelClosing)
-        assertFalse { storeChannelClosing.isSentToDefaultAddress }
-        assertTrue { storeChannelClosing.closingAddress == bobBtcAddr }
+        assertFalse(storeChannelClosing.isSentToDefaultAddress)
+        assertEquals(storeChannelClosing.closingAddress, bobBtcAddr)
     }
 
     @Test
@@ -1590,7 +1562,7 @@ class ClosingTestsCommon : LightningTestSuite() {
     @Test
     fun `recv CMD_CLOSE`() {
         val (alice0, _, _) = initMutualClose()
-        val cmdClose = CMD_CLOSE(null)
+        val cmdClose = CMD_CLOSE(null, null)
         val (_, actions) = alice0.processEx(ChannelEvent.ExecuteCommand(cmdClose))
         val commandError = actions.filterIsInstance<ChannelAction.ProcessCmdRes.NotExecuted>().first()
         assertEquals(cmdClose, commandError.cmd)
@@ -1763,7 +1735,7 @@ class ClosingTestsCommon : LightningTestSuite() {
                 }.flatten()
             }
 
-            val (alice1, bob1, aliceCloseSig) = mutualClose(mutableAlice, mutableBob)
+            val (alice1, bob1, aliceCloseSig) = mutualCloseAlice(mutableAlice, mutableBob)
             val (alice2, bob2) = NegotiatingTestsCommon.converge(alice1, bob1, aliceCloseSig) ?: error("converge should not return null")
 
             return Triple(alice2, bob2, bobCommitTxs)
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NegotiatingTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NegotiatingTestsCommon.kt
index f0c46a4bc..41060f93f 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NegotiatingTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NegotiatingTestsCommon.kt
@@ -5,9 +5,11 @@ import fr.acinq.lightning.Feature
 import fr.acinq.lightning.Lightning.randomKey
 import fr.acinq.lightning.MilliSatoshi
 import fr.acinq.lightning.blockchain.*
+import fr.acinq.lightning.blockchain.fee.FeeratePerKw
 import fr.acinq.lightning.channel.*
 import fr.acinq.lightning.channel.TestsHelper.makeCmdAdd
-import fr.acinq.lightning.channel.TestsHelper.mutualClose
+import fr.acinq.lightning.channel.TestsHelper.mutualCloseAlice
+import fr.acinq.lightning.channel.TestsHelper.mutualCloseBob
 import fr.acinq.lightning.channel.TestsHelper.processEx
 import fr.acinq.lightning.channel.TestsHelper.reachNormal
 import fr.acinq.lightning.tests.TestConstants
@@ -15,124 +17,323 @@ import fr.acinq.lightning.tests.utils.LightningTestSuite
 import fr.acinq.lightning.utils.msat
 import fr.acinq.lightning.utils.sat
 import fr.acinq.lightning.utils.toByteVector
-import fr.acinq.lightning.wire.ClosingSigned
-import fr.acinq.lightning.wire.Error
-import fr.acinq.lightning.wire.Shutdown
-import kotlin.test.Test
-import kotlin.test.assertEquals
-import kotlin.test.assertFalse
-import kotlin.test.assertTrue
+import fr.acinq.lightning.wire.*
+import kotlin.test.*
 
 class NegotiatingTestsCommon : LightningTestSuite() {
 
     @Test
-    fun `correctly sign and detect closing tx`() {
-        // we're fundee here, not funder !!
-        val (bob, alice) = reachNormal()
-        val priv = randomKey()
+    fun `recv CMD_ADD_HTLC`() {
+        val (alice, _, _) = init()
+        val (_, add) = makeCmdAdd(500_000.msat, alice.staticParams.remoteNodeId, TestConstants.defaultBlockHeight.toLong())
+        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(add))
+        assertTrue(alice1 is Negotiating)
+        assertEquals(1, actions1.size)
+        actions1.hasCommandError<ChannelUnavailable>()
+    }
 
-        // Alice initiates a mutual close with a custom final script
-        val finalScript = Script.write(Script.pay2pkh(priv.publicKey())).toByteVector()
-        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(finalScript)))
-        val shutdownA = actions1.findOutgoingMessage<Shutdown>()
+    private fun testClosingSignedDifferentFees(alice: Normal, bob: Normal, bobInitiates: Boolean = false) {
+        // alice and bob see different on-chain feerates
+        val alice1 = alice.updateFeerate(FeeratePerKw(5_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(7_500.sat))
+        val (alice2, bob2, aliceCloseSig1) = if (bobInitiates) mutualCloseBob(alice1, bob1) else mutualCloseAlice(alice1, bob1)
 
-        // Bob replies with Shutdown + ClosingSigned
-        val (bob1, actions2) = bob.processEx(ChannelEvent.MessageReceived(shutdownA))
-        val shutdownB = actions2.findOutgoingMessage<Shutdown>()
-        val closingSignedB = actions2.findOutgoingMessage<ClosingSigned>()
+        // alice is funder so she initiates the negotiation
+        assertEquals(aliceCloseSig1.feeSatoshis, 3370.sat) // matches a feerate of 5000 sat/kw
+        val aliceFeeRange = aliceCloseSig1.tlvStream.get<ClosingSignedTlv.FeeRange>()
+        assertNotNull(aliceFeeRange)
+        assertTrue(aliceFeeRange.min < aliceCloseSig1.feeSatoshis)
+        assertTrue(aliceCloseSig1.feeSatoshis < aliceFeeRange.max)
+        assertEquals(alice2.closingTxProposed.size, 1)
+        assertEquals(alice2.closingTxProposed.last().size, 1)
+        assertNull(alice2.bestUnpublishedClosingTx)
 
-        // Alice agrees with Bob's closing fee, publishes her closing tx and replies with her own ClosingSigned
-        val (alice2, _) = alice1.processEx(ChannelEvent.MessageReceived(shutdownB))
-        val (alice3, actions4) = alice2.processEx(ChannelEvent.MessageReceived(closingSignedB))
-        assertTrue(alice3 is Closing)
-        val closingTxA = actions4.filterIsInstance<ChannelAction.Blockchain.PublishTx>().first().tx
-        val closingSignedA = actions4.findOutgoingMessage<ClosingSigned>()
-        val watch = actions4.findWatch<WatchConfirmed>()
-        assertEquals(watch.txId, closingTxA.txid)
-
-        val fundingTx = Transaction(
-            version = 2,
-            txIn = listOf(TxIn(OutPoint(ByteVector32.Zeroes, 0), TxIn.SEQUENCE_FINAL)),
-            txOut = listOf(bob.commitments.commitInput.txOut),
-            lockTime = 0
-        )
-        assertEquals(fundingTx.txid, closingTxA.txIn[0].outPoint.txid)
-        // check that our closing tx is correctly signed
-        Transaction.correctlySpends(closingTxA, fundingTx, ScriptFlags.STANDARD_SCRIPT_VERIFY_FLAGS)
+        // bob answers with a counter proposition in alice's fee range
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig1))
+        assertTrue(bob3 is Negotiating)
+        val bobCloseSig1 = bobActions3.findOutgoingMessage<ClosingSigned>()
+        assertTrue(aliceFeeRange.min < bobCloseSig1.feeSatoshis)
+        assertTrue(bobCloseSig1.feeSatoshis < aliceFeeRange.max)
+        assertNotNull(bobCloseSig1.tlvStream.get<ClosingSignedTlv.FeeRange>())
+        assertTrue(aliceCloseSig1.feeSatoshis < bobCloseSig1.feeSatoshis)
+        assertNotNull(bob3.bestUnpublishedClosingTx)
 
-        // Bob published his closing tx (which should be the same as Alice's !!!)
-        val (bob2, actions5) = bob1.processEx(ChannelEvent.MessageReceived(closingSignedA))
-        assertTrue(bob2 is Closing)
-        val closingTxB = actions5.filterIsInstance<ChannelAction.Blockchain.PublishTx>().first().tx
-        assertEquals(closingTxA, closingTxB)
+        // alice accepts this proposition
+        val (alice3, aliceActions3) = alice2.processEx(ChannelEvent.MessageReceived(bobCloseSig1))
+        assertTrue(alice3 is Closing)
+        val mutualCloseTx = aliceActions3.findTxs().first()
+        assertEquals(aliceActions3.findWatch<WatchConfirmed>().txId, mutualCloseTx.txid)
+        assertEquals(mutualCloseTx.txOut.size, 2) // NB: anchors are removed from the closing tx
+        val aliceCloseSig2 = aliceActions3.findOutgoingMessage<ClosingSigned>()
+        assertEquals(aliceCloseSig2.feeSatoshis, bobCloseSig1.feeSatoshis)
+        val (bob4, bobActions4) = bob3.processEx(ChannelEvent.MessageReceived(aliceCloseSig2))
+        assertTrue(bob4 is Closing)
+        bobActions4.hasTx(mutualCloseTx)
+        assertEquals(bobActions4.findWatch<WatchConfirmed>().txId, mutualCloseTx.txid)
+        assertEquals(alice3.mutualClosePublished.map { it.tx }, listOf(mutualCloseTx))
+        assertEquals(bob4.mutualClosePublished.map { it.tx }, listOf(mutualCloseTx))
+    }
 
-        // Alice sees Bob's closing tx (which should be the same as the one she published)
-        val (alice4, _) = alice3.processEx(ChannelEvent.WatchReceived(WatchEventSpent(alice3.channelId, BITCOIN_FUNDING_SPENT, closingTxB)))
-        assertTrue(alice4 is Closing)
+    @Test
+    fun `recv ClosingSigned (theirCloseFee != ourCloseFee)`() {
+        val (alice, bob) = reachNormal()
+        testClosingSignedDifferentFees(alice, bob)
+    }
 
-        val (alice5, _) = alice4.processEx(ChannelEvent.WatchReceived(WatchEventConfirmed(alice3.channelId, BITCOIN_TX_CONFIRMED(closingTxA), 144, 0, closingTxA)))
-        assertTrue(alice5 is Closed)
+    @Test
+    fun `recv ClosingSigned (theirCloseFee != ourCloseFee, bob starts closing)`() {
+        val (alice, bob) = reachNormal()
+        testClosingSignedDifferentFees(alice, bob, bobInitiates = true)
     }
 
     @Test
-    fun `recv CMD_ADD_HTLC`() {
-        val (alice, _, _) = init()
-        val (_, add) = makeCmdAdd(500_000.msat, alice.staticParams.remoteNodeId, TestConstants.defaultBlockHeight.toLong())
-        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(add))
-        assertTrue(alice1 is Negotiating)
-        assertEquals(1, actions1.size)
-        actions1.hasCommandError<ChannelUnavailable>()
+    fun `recv ClosingSigned (theirMinCloseFee greater than ourCloseFee)`() {
+        val (alice, bob) = reachNormal()
+        val alice1 = alice.updateFeerate(FeeratePerKw(10_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(2_500.sat))
+
+        val (_, bob2, aliceCloseSig) = mutualCloseAlice(alice1, bob1)
+        val (bob3, actions) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
+        assertTrue(bob3 is Closing)
+        val bobCloseSig = actions.findOutgoingMessage<ClosingSigned>()
+        assertEquals(bobCloseSig.feeSatoshis, aliceCloseSig.feeSatoshis)
     }
 
     @Test
-    fun `recv ClosingSigned (theirCloseFee != ourCloseFee)`() {
-        val (alice, bob, aliceCloseSig) = init()
-        val (_, actions) = bob.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
-        // Bob answers with a counter proposition
+    fun `recv ClosingSigned (theirMaxCloseFee smaller than ourCloseFee)`() {
+        val (alice, bob) = reachNormal()
+        val alice1 = alice.updateFeerate(FeeratePerKw(5_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(20_000.sat))
+
+        val (_, bob2, aliceCloseSig) = mutualCloseAlice(alice1, bob1)
+        val (_, actions) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
         val bobCloseSig = actions.findOutgoingMessage<ClosingSigned>()
-        assertTrue { aliceCloseSig.feeSatoshis > bobCloseSig.feeSatoshis }
-        val (alice1, actions1) = alice.processEx(ChannelEvent.MessageReceived(bobCloseSig))
-        val aliceCloseSig1 = actions1.findOutgoingMessage<ClosingSigned>()
-        // BOLT 2: If the receiver [doesn't agree with the fee] it SHOULD propose a value strictly between the received fee-satoshis and its previously-sent fee-satoshis
-        assertTrue { aliceCloseSig1.feeSatoshis < aliceCloseSig.feeSatoshis && aliceCloseSig1.feeSatoshis > bobCloseSig.feeSatoshis }
-        assertEquals((alice1 as Negotiating).closingTxProposed.last().map { it.localClosingSigned }, alice.closingTxProposed.last().map { it.localClosingSigned } + listOf(aliceCloseSig1))
+        assertEquals(bobCloseSig.feeSatoshis, aliceCloseSig.tlvStream.get<ClosingSignedTlv.FeeRange>()!!.max)
+    }
+
+    private fun testClosingSignedSameFees(alice: Normal, bob: Normal, bobInitiates: Boolean = false) {
+        val alice1 = alice.updateFeerate(FeeratePerKw(5_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(5_000.sat))
+        val (alice2, bob2, aliceCloseSig1) = if (bobInitiates) mutualCloseBob(alice1, bob1) else mutualCloseAlice(alice1, bob1)
+
+        // alice is funder so she initiates the negotiation
+        assertEquals(aliceCloseSig1.feeSatoshis, 3370.sat) // matches a feerate of 5000 sat/kw
+        val aliceFeeRange = aliceCloseSig1.tlvStream.get<ClosingSignedTlv.FeeRange>()
+        assertNotNull(aliceFeeRange)
+
+        // bob agrees with that proposal
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig1))
+        assertTrue(bob3 is Closing)
+        val bobCloseSig1 = bobActions3.findOutgoingMessage<ClosingSigned>()
+        assertNotNull(bobCloseSig1.tlvStream.get<ClosingSignedTlv.FeeRange>())
+        assertEquals(aliceCloseSig1.feeSatoshis, bobCloseSig1.feeSatoshis)
+        val mutualCloseTx = bobActions3.findTxs().first()
+        assertEquals(mutualCloseTx.txOut.size, 2) // NB: anchors are removed from the closing tx
+
+        val (alice3, aliceActions3) = alice2.processEx(ChannelEvent.MessageReceived(bobCloseSig1))
+        assertTrue(alice3 is Closing)
+        aliceActions3.hasTx(mutualCloseTx)
     }
 
     @Test
     fun `recv ClosingSigned (theirCloseFee == ourCloseFee)`() {
-        val (alice, bob, aliceCloseSig) = init()
-        assertTrue { converge(alice, bob, aliceCloseSig) != null }
+        val (alice, bob) = reachNormal()
+        testClosingSignedSameFees(alice, bob)
+    }
+
+    @Test
+    fun `recv ClosingSigned (theirCloseFee == ourCloseFee, bob starts closing)`() {
+        val (alice, bob) = reachNormal()
+        testClosingSignedSameFees(alice, bob, bobInitiates = true)
+    }
+
+    @Test
+    fun `override on-chain fee estimator (funder)`() {
+        val (alice, bob) = reachNormal()
+        val alice1 = alice.updateFeerate(FeeratePerKw(10_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(10_000.sat))
+
+        // alice initiates the negotiation with a very low feerate
+        val (alice2, bob2, aliceCloseSig) = mutualCloseAlice(alice1, bob1, feerates = ClosingFeerates(FeeratePerKw(2_500.sat), FeeratePerKw(2_000.sat), FeeratePerKw(3_000.sat)))
+        assertEquals(aliceCloseSig.feeSatoshis, 1685.sat)
+        assertEquals(aliceCloseSig.tlvStream.get<ClosingSignedTlv.FeeRange>(), ClosingSignedTlv.FeeRange(1348.sat, 2022.sat))
+
+        // bob chooses alice's highest fee
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
+        val bobCloseSig = bobActions3.findOutgoingMessage<ClosingSigned>()
+        assertEquals(bobCloseSig.feeSatoshis, 2022.sat)
+
+        // alice accepts this proposition
+        val (alice3, aliceActions3) = alice2.processEx(ChannelEvent.MessageReceived(bobCloseSig))
+        assertTrue(alice3 is Closing)
+        val mutualCloseTx = aliceActions3.findTxs().first()
+        val aliceCloseSig2 = aliceActions3.findOutgoingMessage<ClosingSigned>()
+        assertEquals(aliceCloseSig2.feeSatoshis, 2022.sat)
+
+        val (bob4, bobActions4) = bob3.processEx(ChannelEvent.MessageReceived(aliceCloseSig2))
+        assertTrue(bob4 is Closing)
+        bobActions4.hasTx(mutualCloseTx)
     }
 
     @Test
-    fun `recv ClosingSigned (theirCloseFee == ourCloseFee, different fee parameters)`() {
-        val (alice, bob, aliceCloseSig) = init(tweakFees = true)
-        assertTrue { converge(alice, bob, aliceCloseSig) != null }
+    fun `override on-chain fee estimator (fundee)`() {
+        val (alice, bob) = reachNormal()
+        val alice1 = alice.updateFeerate(FeeratePerKw(10_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(10_000.sat))
+
+        // alice is funder, so bob's override will simply be ignored
+        val (alice2, bob2, aliceCloseSig) = mutualCloseBob(alice1, bob1, feerates = ClosingFeerates(FeeratePerKw(2_500.sat), FeeratePerKw(2_000.sat), FeeratePerKw(3_000.sat)))
+        assertEquals(aliceCloseSig.feeSatoshis, 6740.sat) // matches a feerate of 10 000 sat/kw
+
+        // bob directly agrees because their fee estimator matches
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
+        assertTrue(bob3 is Closing)
+        val mutualCloseTx = bobActions3.findTxs().first()
+        val bobCloseSig = bobActions3.findOutgoingMessage<ClosingSigned>()
+        assertEquals(bobCloseSig.feeSatoshis, aliceCloseSig.feeSatoshis)
+
+        // alice accepts this proposition
+        val (alice3, aliceActions3) = alice2.processEx(ChannelEvent.MessageReceived(bobCloseSig))
+        assertTrue(alice3 is Closing)
+        aliceActions3.hasTx(mutualCloseTx)
     }
 
     @Test
     fun `recv ClosingSigned (nothing at stake)`() {
-        val (alice, bob, aliceCloseSig) = init(pushMsat = 0.msat)
+        val (alice, bob) = reachNormal(pushMsat = 0.msat)
+        val alice1 = alice.updateFeerate(FeeratePerKw(5_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(10_000.sat))
+
         // Bob has nothing at stake
-        val (bob1, actions) = bob.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
-        assertTrue(bob1 is Closing)
-        val mutualCloseTxBob = actions.findTxs().first()
-        val bobCloseSig = actions.findOutgoingMessage<ClosingSigned>()
-        assertEquals(aliceCloseSig.feeSatoshis, bobCloseSig.feeSatoshis)
-        val (alice1, actions1) = alice.processEx(ChannelEvent.MessageReceived(bobCloseSig))
-        assertTrue(alice1 is Closing)
-        val mutualCloseTxAlice = actions1.findTxs().first()
-        assertEquals(mutualCloseTxAlice, mutualCloseTxBob)
-        assertEquals(actions.findWatches<WatchConfirmed>().map { it.event }, listOf(BITCOIN_TX_CONFIRMED(mutualCloseTxBob)))
-        assertEquals(actions1.findWatches<WatchConfirmed>().map { it.event }, listOf(BITCOIN_TX_CONFIRMED(mutualCloseTxBob)))
-        assertEquals(bob1.mutualClosePublished.map { it.tx }, listOf(mutualCloseTxBob))
-        assertEquals(alice1.mutualClosePublished.map { it.tx }, listOf(mutualCloseTxBob))
+        val (_, bob2, aliceCloseSig) = mutualCloseBob(alice1, bob1)
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
+        assertTrue(bob3 is Closing)
+        val mutualCloseTx = bobActions3.findTxs().first()
+        assertEquals(bob3.mutualClosePublished.map { it.tx }, listOf(mutualCloseTx))
+        assertEquals(bobActions3.findWatches<WatchConfirmed>().map { it.event }, listOf(BITCOIN_TX_CONFIRMED(mutualCloseTx)))
+    }
+
+    @Test
+    fun `recv ClosingSigned (other side ignores our fee range, funder)`() {
+        val (alice, bob) = reachNormal()
+        val alice1 = alice.updateFeerate(FeeratePerKw(1_000.sat))
+        val (alice2, bob2, aliceCloseSig1) = mutualCloseAlice(alice1, bob)
+        val aliceFeeRange = aliceCloseSig1.tlvStream.get<ClosingSignedTlv.FeeRange>()
+        assertNotNull(aliceFeeRange)
+        assertEquals(aliceCloseSig1.feeSatoshis, 674.sat)
+        assertEquals(aliceFeeRange.max, 1348.sat)
+        assertEquals(alice2.closingTxProposed.last().size, 1)
+        assertNull(alice2.bestUnpublishedClosingTx)
+
+        // bob makes a proposal outside our fee range
+        val (_, bobCloseSig1) = makeLegacyClosingSigned(alice2, bob2, 2_500.sat)
+        val (alice3, actions3) = alice2.processEx(ChannelEvent.MessageReceived(bobCloseSig1))
+        assertTrue(alice3 is Negotiating)
+        val aliceCloseSig2 = actions3.findOutgoingMessage<ClosingSigned>()
+        assertTrue(aliceCloseSig1.feeSatoshis < aliceCloseSig2.feeSatoshis)
+        assertTrue(aliceCloseSig2.feeSatoshis < 1600.sat)
+        assertEquals(alice3.closingTxProposed.last().size, 2)
+        assertNotNull(alice3.bestUnpublishedClosingTx)
+
+        val (_, bobCloseSig2) = makeLegacyClosingSigned(alice2, bob2, 2_000.sat)
+        val (alice4, actions4) = alice3.processEx(ChannelEvent.MessageReceived(bobCloseSig2))
+        assertTrue(alice4 is Negotiating)
+        val aliceCloseSig3 = actions4.findOutgoingMessage<ClosingSigned>()
+        assertTrue(aliceCloseSig2.feeSatoshis < aliceCloseSig3.feeSatoshis)
+        assertTrue(aliceCloseSig3.feeSatoshis < 1800.sat)
+        assertEquals(alice4.closingTxProposed.last().size, 3)
+        assertNotNull(alice4.bestUnpublishedClosingTx)
+
+        val (_, bobCloseSig3) = makeLegacyClosingSigned(alice2, bob2, 1_800.sat)
+        val (alice5, actions5) = alice4.processEx(ChannelEvent.MessageReceived(bobCloseSig3))
+        assertTrue(alice5 is Negotiating)
+        val aliceCloseSig4 = actions5.findOutgoingMessage<ClosingSigned>()
+        assertTrue(aliceCloseSig3.feeSatoshis < aliceCloseSig4.feeSatoshis)
+        assertTrue(aliceCloseSig4.feeSatoshis < 1800.sat)
+        assertEquals(alice5.closingTxProposed.last().size, 4)
+        assertNotNull(alice5.bestUnpublishedClosingTx)
+
+        val (_, bobCloseSig4) = makeLegacyClosingSigned(alice2, bob2, aliceCloseSig4.feeSatoshis)
+        val (alice6, actions6) = alice5.processEx(ChannelEvent.MessageReceived(bobCloseSig4))
+        assertTrue(alice6 is Closing)
+        val mutualCloseTx = actions6.findTxs().first()
+        assertEquals(alice6.mutualClosePublished.size, 1)
+        assertEquals(mutualCloseTx, alice6.mutualClosePublished.first().tx)
+    }
+
+    @Test
+    fun `recv ClosingSigned (other side ignores our fee range, fundee)`() {
+        val (alice, bob) = reachNormal()
+        val bob1 = bob.updateFeerate(FeeratePerKw(10_000.sat))
+        val (alice2, bob2, _) = mutualCloseBob(alice, bob1)
+
+        // alice starts with a very low proposal
+        val (aliceCloseSig1, _) = makeLegacyClosingSigned(alice2, bob2, 500.sat)
+        val (bob3, actions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig1))
+        assertTrue(bob3 is Negotiating)
+        val bobCloseSig1 = actions3.findOutgoingMessage<ClosingSigned>()
+        assertTrue(3000.sat < bobCloseSig1.feeSatoshis)
+        assertEquals(bob3.closingTxProposed.last().size, 1)
+        assertNotNull(bob3.bestUnpublishedClosingTx)
+
+        val (aliceCloseSig2, _) = makeLegacyClosingSigned(alice2, bob2, 750.sat)
+        val (bob4, actions4) = bob3.processEx(ChannelEvent.MessageReceived(aliceCloseSig2))
+        assertTrue(bob4 is Negotiating)
+        val bobCloseSig2 = actions4.findOutgoingMessage<ClosingSigned>()
+        assertTrue(2000.sat < bobCloseSig2.feeSatoshis)
+        assertEquals(bob4.closingTxProposed.last().size, 2)
+        assertNotNull(bob4.bestUnpublishedClosingTx)
+
+        val (aliceCloseSig3, _) = makeLegacyClosingSigned(alice2, bob2, 1000.sat)
+        val (bob5, actions5) = bob4.processEx(ChannelEvent.MessageReceived(aliceCloseSig3))
+        assertTrue(bob5 is Negotiating)
+        val bobCloseSig3 = actions5.findOutgoingMessage<ClosingSigned>()
+        assertTrue(1500.sat < bobCloseSig3.feeSatoshis)
+        assertEquals(bob5.closingTxProposed.last().size, 3)
+        assertNotNull(bob5.bestUnpublishedClosingTx)
+
+        val (aliceCloseSig4, _) = makeLegacyClosingSigned(alice2, bob2, 1300.sat)
+        val (bob6, actions6) = bob5.processEx(ChannelEvent.MessageReceived(aliceCloseSig4))
+        assertTrue(bob6 is Negotiating)
+        val bobCloseSig4 = actions6.findOutgoingMessage<ClosingSigned>()
+        assertTrue(1300.sat < bobCloseSig4.feeSatoshis)
+        assertEquals(bob6.closingTxProposed.last().size, 4)
+        assertNotNull(bob6.bestUnpublishedClosingTx)
+
+        val (aliceCloseSig5, _) = makeLegacyClosingSigned(alice2, bob2, bobCloseSig4.feeSatoshis)
+        val (bob7, actions7) = bob6.processEx(ChannelEvent.MessageReceived(aliceCloseSig5))
+        assertTrue(bob7 is Closing)
+        val mutualCloseTx = actions7.findTxs().first()
+        assertEquals(bob7.mutualClosePublished.size, 1)
+        assertEquals(mutualCloseTx, bob7.mutualClosePublished.first().tx)
+    }
+
+    @Test
+    fun `recv ClosingSigned (other side ignores our fee range, max iterations reached)`() {
+        val (alice, bob) = reachNormal()
+        val alice1 = alice.updateFeerate(FeeratePerKw(1_000.sat))
+        val (alice2, bob2, aliceCloseSig1) = mutualCloseAlice(alice1, bob)
+        var mutableAlice = alice2 as ChannelStateWithCommitments
+        var aliceCloseSig = aliceCloseSig1
+
+        for (i in 1..Channel.MAX_NEGOTIATION_ITERATIONS) {
+            val feeRange = aliceCloseSig.tlvStream.get<ClosingSignedTlv.FeeRange>()
+            assertNotNull(feeRange)
+            val bobNextFee = (aliceCloseSig.feeSatoshis + 500.sat).max(feeRange.max + 1.sat)
+            val (_, bobClosing) = makeLegacyClosingSigned(alice2, bob2, bobNextFee)
+            val (aliceNew, actions) = mutableAlice.processEx(ChannelEvent.MessageReceived(bobClosing))
+            aliceCloseSig = actions.findOutgoingMessage<ClosingSigned>()
+            mutableAlice = aliceNew as ChannelStateWithCommitments
+        }
+
+        assertTrue(mutableAlice is Closing)
+        assertEquals(mutableAlice.mutualClosePublished.size, 1)
     }
 
     @Test
     fun `recv ClosingSigned (invalid signature)`() {
         val (_, bob, aliceCloseSig) = init()
-        val (bob1, actions) = bob.processEx(ChannelEvent.MessageReceived(aliceCloseSig.copy(feeSatoshis = 99000.sat)))
+        val (bob1, actions) = bob.processEx(ChannelEvent.MessageReceived(aliceCloseSig.copy(feeSatoshis = 99_000.sat)))
         assertTrue(bob1 is Closing)
         actions.hasOutgoingMessage<Error>()
         actions.hasWatch<WatchConfirmed>()
@@ -150,37 +351,92 @@ class NegotiatingTestsCommon : LightningTestSuite() {
         assertFalse(bobCloseSig.channelData.isEmpty())
     }
 
+    @Test
+    fun `recv BITCOIN_FUNDING_SPENT (counterparty's mutual close)`() {
+        // NB: we're fundee here, not funder
+        val (bob, alice) = reachNormal()
+        val priv = randomKey()
+
+        // Alice initiates a mutual close with a custom final script
+        val finalScript = Script.write(Script.pay2pkh(priv.publicKey())).toByteVector()
+        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(finalScript, null)))
+        val shutdownA = actions1.findOutgoingMessage<Shutdown>()
+
+        // Bob replies with Shutdown + ClosingSigned
+        val (bob1, actions2) = bob.processEx(ChannelEvent.MessageReceived(shutdownA))
+        val shutdownB = actions2.findOutgoingMessage<Shutdown>()
+        val closingSignedB = actions2.findOutgoingMessage<ClosingSigned>()
+
+        // Alice agrees with Bob's closing fee, publishes her closing tx and replies with her own ClosingSigned
+        val (alice2, _) = alice1.processEx(ChannelEvent.MessageReceived(shutdownB))
+        val (alice3, actions4) = alice2.processEx(ChannelEvent.MessageReceived(closingSignedB))
+        assertTrue(alice3 is Closing)
+        val closingTxA = actions4.filterIsInstance<ChannelAction.Blockchain.PublishTx>().first().tx
+        val closingSignedA = actions4.findOutgoingMessage<ClosingSigned>()
+        val watch = actions4.findWatch<WatchConfirmed>()
+        assertEquals(watch.txId, closingTxA.txid)
+
+        val fundingTx = Transaction(
+            version = 2,
+            txIn = listOf(TxIn(OutPoint(ByteVector32.Zeroes, 0), TxIn.SEQUENCE_FINAL)),
+            txOut = listOf(bob.commitments.commitInput.txOut),
+            lockTime = 0
+        )
+        assertEquals(fundingTx.txid, closingTxA.txIn[0].outPoint.txid)
+        // check that our closing tx is correctly signed
+        Transaction.correctlySpends(closingTxA, fundingTx, ScriptFlags.STANDARD_SCRIPT_VERIFY_FLAGS)
+
+        // Bob published his closing tx (which should be the same as Alice's)
+        val (bob2, actions5) = bob1.processEx(ChannelEvent.MessageReceived(closingSignedA))
+        assertTrue(bob2 is Closing)
+        val closingTxB = actions5.filterIsInstance<ChannelAction.Blockchain.PublishTx>().first().tx
+        assertEquals(closingTxA, closingTxB)
+
+        // Alice sees Bob's closing tx (which should be the same as the one she published)
+        val (alice4, _) = alice3.processEx(ChannelEvent.WatchReceived(WatchEventSpent(alice3.channelId, BITCOIN_FUNDING_SPENT, closingTxB)))
+        assertTrue(alice4 is Closing)
+
+        val (alice5, _) = alice4.processEx(ChannelEvent.WatchReceived(WatchEventConfirmed(alice3.channelId, BITCOIN_TX_CONFIRMED(closingTxA), 144, 0, closingTxA)))
+        assertTrue(alice5 is Closed)
+    }
+
     @Test
     fun `recv BITCOIN_FUNDING_SPENT (an older mutual close)`() {
-        val (alice, bob, aliceCloseSig) = init()
-        val (bob1, actions) = bob.processEx(ChannelEvent.MessageReceived(aliceCloseSig))
-        assertTrue(bob1 is Negotiating)
-        val bobCloseSig = actions.findOutgoingMessage<ClosingSigned>()
-        val (alice1, actions1) = alice.processEx(ChannelEvent.MessageReceived(bobCloseSig))
-        val aliceCloseSig1 = actions1.findOutgoingMessage<ClosingSigned>()
-        assertTrue(bobCloseSig.feeSatoshis != aliceCloseSig1.feeSatoshis)
-        // at this point alice and bob have not yet converged on closing fees, but bob decides to publish a mutual close with one of the previous sigs
-        val bobClosingTx = Helpers.Closing.checkClosingSignature(
-            bob1.keyManager,
-            bob1.commitments,
-            bob1.localShutdown.scriptPubKey.toByteArray(),
-            bob1.remoteShutdown.scriptPubKey.toByteArray(),
-            aliceCloseSig1.feeSatoshis,
-            aliceCloseSig1.signature
-        ).right!!
-        val (alice2, actionsAlice2) = alice1.processEx(ChannelEvent.WatchReceived(WatchEventSpent(alice.channelId, BITCOIN_FUNDING_SPENT, bobClosingTx.tx)))
-        assertTrue(alice2 is Closing)
-        actionsAlice2.has<ChannelAction.Storage.StoreState>()
-        actionsAlice2.hasTx(bobClosingTx.tx)
-        assertEquals(actionsAlice2.hasWatch<WatchConfirmed>().txId, bobClosingTx.tx.txid)
+        val (alice, bob) = reachNormal()
+        val alice1 = alice.updateFeerate(FeeratePerKw(1_000.sat))
+        val bob1 = bob.updateFeerate(FeeratePerKw(10_000.sat))
+        val (alice2, bob2, aliceCloseSig1) = mutualCloseAlice(alice1, bob1)
+
+        val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(aliceCloseSig1))
+        assertTrue(bob3 is Negotiating)
+        bobActions3.findOutgoingMessage<ClosingSigned>()
+        val firstMutualCloseTx = bob3.bestUnpublishedClosingTx
+        assertNotNull(firstMutualCloseTx)
+
+        val (_, bobCloseSig1) = makeLegacyClosingSigned(alice2, bob2, 3_000.sat)
+        assertNotEquals(bobCloseSig1.feeSatoshis, aliceCloseSig1.feeSatoshis)
+        val (alice3, aliceActions3) = alice2.processEx(ChannelEvent.MessageReceived(bobCloseSig1))
+        assertTrue(alice3 is Negotiating)
+        val aliceCloseSig2 = aliceActions3.findOutgoingMessage<ClosingSigned>()
+        assertNotEquals(aliceCloseSig2.feeSatoshis, bobCloseSig1.feeSatoshis)
+        val latestMutualCloseTx = alice3.bestUnpublishedClosingTx
+        assertNotNull(latestMutualCloseTx)
+        assertNotEquals(firstMutualCloseTx.tx.txid, latestMutualCloseTx.tx.txid)
+
+        // at this point bob will receive a new signature, but he decides instead to publish the first mutual close
+        val (alice4, aliceActions4) = alice3.processEx(ChannelEvent.WatchReceived(WatchEventSpent(alice3.channelId, BITCOIN_FUNDING_SPENT, firstMutualCloseTx.tx)))
+        assertTrue(alice4 is Closing)
+        aliceActions4.has<ChannelAction.Storage.StoreState>()
+        aliceActions4.hasTx(firstMutualCloseTx.tx)
+        assertEquals(aliceActions4.hasWatch<WatchConfirmed>().txId, firstMutualCloseTx.tx.txid)
     }
 
     @Test
     fun `recv CMD_CLOSE`() {
         val (alice, _, _) = init()
-        val (alice1, actions) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice1, actions) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertEquals(alice1, alice)
-        assertEquals(actions, listOf(ChannelAction.ProcessCmdRes.NotExecuted(CMD_CLOSE(null), ClosingAlreadyInProgress(alice.channelId))))
+        assertEquals(actions, listOf(ChannelAction.ProcessCmdRes.NotExecuted(CMD_CLOSE(null, null), ClosingAlreadyInProgress(alice.channelId))))
     }
 
     @Test
@@ -188,14 +444,22 @@ class NegotiatingTestsCommon : LightningTestSuite() {
         val (alice, _, _) = init()
         val (alice1, actions) = alice.processEx(ChannelEvent.MessageReceived(Error(ByteVector32.Zeroes, "oops")))
         assertTrue(alice1 is Closing)
-        assertTrue(actions.findTxs().contains(alice.commitments.localCommit.publishableTxs.commitTx.tx))
+        actions.hasTx(alice.commitments.localCommit.publishableTxs.commitTx.tx)
         assertTrue(actions.findWatches<WatchConfirmed>().map { it.event }.contains(BITCOIN_TX_CONFIRMED(alice.commitments.localCommit.publishableTxs.commitTx.tx)))
     }
 
     companion object {
-        fun init(channelType: ChannelType.SupportedChannelType = ChannelType.SupportedChannelType.AnchorOutputs, tweakFees: Boolean = false, pushMsat: MilliSatoshi = TestConstants.pushMsat): Triple<Negotiating, Negotiating, ClosingSigned> {
+        fun init(channelType: ChannelType.SupportedChannelType = ChannelType.SupportedChannelType.AnchorOutputs, pushMsat: MilliSatoshi = TestConstants.pushMsat): Triple<Negotiating, Negotiating, ClosingSigned> {
             val (alice, bob) = reachNormal(channelType = channelType, pushMsat = pushMsat)
-            return mutualClose(alice, bob, tweakFees)
+            return mutualCloseAlice(alice, bob)
+        }
+
+        private fun makeLegacyClosingSigned(alice: Negotiating, bob: Negotiating, closingFee: Satoshi): Pair<ClosingSigned, ClosingSigned> {
+            val aliceScript = alice.localShutdown.scriptPubKey.toByteArray()
+            val bobScript = bob.localShutdown.scriptPubKey.toByteArray()
+            val (_, aliceClosingSigned) = Helpers.Closing.makeClosingTx(alice.keyManager, alice.commitments, aliceScript, bobScript, ClosingFees(closingFee, closingFee, closingFee))
+            val (_, bobClosingSigned) = Helpers.Closing.makeClosingTx(bob.keyManager, bob.commitments, bobScript, aliceScript, ClosingFees(closingFee, closingFee, closingFee))
+            return Pair(aliceClosingSigned.copy(tlvStream = TlvStream.empty()), bobClosingSigned.copy(tlvStream = TlvStream.empty()))
         }
 
         tailrec fun converge(a: ChannelState, b: ChannelState, aliceCloseSig: ClosingSigned?): Pair<Closing, Closing>? {
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NormalTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NormalTestsCommon.kt
index 2f06fdabc..6b3931d91 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NormalTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/NormalTestsCommon.kt
@@ -319,7 +319,7 @@ class NormalTestsCommon : LightningTestSuite() {
     @Test
     fun `recv CMD_ADD_HTLC (after having sent Shutdown)`() {
         val (alice0, _) = reachNormal()
-        val (alice1, actionsAlice1) = alice0.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice1, actionsAlice1) = alice0.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         actionsAlice1.findOutgoingMessage<Shutdown>()
         assertTrue(alice1 is Normal && alice1.localShutdown != null && alice1.remoteShutdown == null)
 
@@ -338,7 +338,7 @@ class NormalTestsCommon : LightningTestSuite() {
         actionsAlice1.findOutgoingMessage<UpdateAddHtlc>()
 
         // at the same time bob initiates a closing
-        val (_, actionsBob1) = bob0.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (_, actionsBob1) = bob0.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         val shutdown = actionsBob1.findOutgoingMessage<Shutdown>()
 
         val (alice2, _) = alice1.processEx(ChannelEvent.MessageReceived(shutdown))
@@ -1377,7 +1377,7 @@ class NormalTestsCommon : LightningTestSuite() {
     fun `recv CMD_CLOSE (no pending htlcs)`() {
         val (alice, _) = reachNormal()
         assertNull(alice.localShutdown)
-        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice1 is Normal)
         actions1.hasOutgoingMessage<Shutdown>()
         assertNotNull(alice1.localShutdown)
@@ -1388,7 +1388,7 @@ class NormalTestsCommon : LightningTestSuite() {
         val (alice, bob) = reachNormal()
         val (nodes, _, _) = addHtlc(1000.msat, payer = alice, payee = bob)
         val (alice1, _) = nodes
-        val (alice2, actions1) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice2, actions1) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice2 is Normal)
         actions1.hasCommandError<CannotCloseWithUnsignedOutgoingHtlcs>()
     }
@@ -1398,7 +1398,7 @@ class NormalTestsCommon : LightningTestSuite() {
         val (alice, bob) = reachNormal()
         val (nodes, _, _) = addHtlc(1000.msat, payer = alice, payee = bob)
         val (_, bob1) = nodes
-        val (bob2, actions1) = bob1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob2, actions1) = bob1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(bob2 is Normal)
         actions1.hasOutgoingMessage<Shutdown>()
         assertNotNull(bob2.localShutdown)
@@ -1408,7 +1408,7 @@ class NormalTestsCommon : LightningTestSuite() {
     fun `recv CMD_CLOSE (with invalid final script)`() {
         val (alice, _) = reachNormal()
         assertNull(alice.localShutdown)
-        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(ByteVector("00112233445566778899"))))
+        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(ByteVector("00112233445566778899"), null)))
         assertTrue(alice1 is Normal)
         actions1.hasCommandError<InvalidFinalScript>()
     }
@@ -1418,7 +1418,7 @@ class NormalTestsCommon : LightningTestSuite() {
         val (alice, bob) = reachNormal()
         val (nodes, _, _) = addHtlc(1000.msat, payer = alice, payee = bob)
         val (alice1, _) = crossSign(nodes.first, nodes.second)
-        val (alice2, actions1) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice2, actions1) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         actions1.hasOutgoingMessage<Shutdown>()
         assertTrue(alice2 is Normal)
         assertNotNull(alice2.localShutdown)
@@ -1428,11 +1428,11 @@ class NormalTestsCommon : LightningTestSuite() {
     fun `recv CMD_CLOSE (two in a row)`() {
         val (alice, _) = reachNormal()
         assertNull(alice.localShutdown)
-        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice1 is Normal)
         actions1.hasOutgoingMessage<Shutdown>()
         assertNotNull(alice1.localShutdown)
-        val (alice2, actions2) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice2, actions2) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice2 is Normal)
         actions2.hasCommandError<ClosingAlreadyInProgress>()
     }
@@ -1444,7 +1444,7 @@ class NormalTestsCommon : LightningTestSuite() {
         val (alice1, actions1) = nodes.first.processEx(ChannelEvent.ExecuteCommand(CMD_SIGN))
         assertTrue(alice1 is Normal)
         actions1.hasOutgoingMessage<CommitSig>()
-        val (alice2, actions2) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice2, actions2) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice2 is Normal)
         actions2.hasOutgoingMessage<Shutdown>()
     }
@@ -1454,10 +1454,10 @@ class NormalTestsCommon : LightningTestSuite() {
         val (alice, _) = reachNormal()
         val (alice1, actions1) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_UPDATE_FEE(FeeratePerKw(20_000.sat), false)))
         actions1.hasOutgoingMessage<UpdateFee>()
-        val (alice2, actions2) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice2, actions2) = alice1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         actions2.hasCommandError<CannotCloseWithUnsignedOutgoingUpdateFee>()
         val (alice3, _) = alice2.processEx(ChannelEvent.ExecuteCommand(CMD_SIGN))
-        val (alice4, actions4) = alice3.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice4, actions4) = alice3.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice4 is Normal)
         actions4.hasOutgoingMessage<Shutdown>()
     }
@@ -1475,7 +1475,7 @@ class NormalTestsCommon : LightningTestSuite() {
     fun `recv Shutdown (with unacked sent htlcs)`() {
         val (alice, bob) = reachNormal()
         val (nodes, _, _) = addHtlc(50000000.msat, payer = alice, payee = bob)
-        val (bob1, actions1) = nodes.second.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob1, actions1) = nodes.second.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
 
         val shutdown = actions1.findOutgoingMessage<Shutdown>()
         val (alice1, actions2) = nodes.first.processEx(ChannelEvent.MessageReceived(shutdown))
@@ -1515,7 +1515,7 @@ class NormalTestsCommon : LightningTestSuite() {
 
         // Bob initiates a close before receiving the signature.
         val (bob1, _) = bob.processEx(ChannelEvent.MessageReceived(updateFee))
-        val (bob2, bobActions2) = bob1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob2, bobActions2) = bob1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         val shutdownBob = bobActions2.hasOutgoingMessage<Shutdown>()
 
         val (bob3, bobActions3) = bob2.processEx(ChannelEvent.MessageReceived(sigAlice))
@@ -1556,7 +1556,7 @@ class NormalTestsCommon : LightningTestSuite() {
         val (alice, bob) = reachNormal()
         val (nodes, _, _) = addHtlc(50000000.msat, payer = alice, payee = bob)
         val (_, bob1) = crossSign(nodes.first, nodes.second)
-        val (bob2, actions1) = bob1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob2, actions1) = bob1.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         actions1.hasOutgoingMessage<Shutdown>()
 
         // actual test begins
@@ -1585,7 +1585,7 @@ class NormalTestsCommon : LightningTestSuite() {
         val (nodes, _, _) = addHtlc(50000000.msat, payer = alice, payee = bob)
         val (alice1, actions1) = nodes.first.processEx(ChannelEvent.ExecuteCommand(CMD_SIGN))
         actions1.hasOutgoingMessage<CommitSig>()
-        val (_, actions2) = bob.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (_, actions2) = bob.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         val shutdown = actions2.findOutgoingMessage<Shutdown>()
 
         // actual test begins
@@ -1598,7 +1598,7 @@ class NormalTestsCommon : LightningTestSuite() {
     fun `recv Shutdown (while waiting for a RevokeAndAck with pending outgoing htlc)`() {
         val (alice, bob) = reachNormal()
         // let's make bob send a Shutdown message
-        val (bob1, actions1) = bob.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob1, actions1) = bob.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         val shutdown = actions1.findOutgoingMessage<Shutdown>()
 
         // this is just so we have something to sign
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ShutdownTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ShutdownTestsCommon.kt
index db3850ebe..b26354431 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ShutdownTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/ShutdownTestsCommon.kt
@@ -361,7 +361,7 @@ class ShutdownTestsCommon : LightningTestSuite() {
         val (_, bob0) = reachNormal()
         assertTrue(bob0.commitments.localParams.features.hasFeature(Feature.ChannelBackupClient))
         assertFalse(bob0.commitments.channelFeatures.hasFeature(Feature.ChannelBackupClient)) // this isn't a permanent channel feature
-        val (bob1, actions1) = bob0.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob1, actions1) = bob0.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(bob1 is Normal)
         val blob = Serialization.encrypt(bob1.staticParams.nodeParams.nodePrivateKey.value, bob1)
         val shutdown = actions1.findOutgoingMessage<Shutdown>()
@@ -479,9 +479,9 @@ class ShutdownTestsCommon : LightningTestSuite() {
     @Test
     fun `recv CMD_CLOSE`() {
         val (alice, _) = init()
-        val (alice1, actions) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice1, actions) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertEquals(alice1, alice)
-        assertEquals(actions, listOf(ChannelAction.ProcessCmdRes.NotExecuted(CMD_CLOSE(null), ClosingAlreadyInProgress(alice.channelId))))
+        assertEquals(actions, listOf(ChannelAction.ProcessCmdRes.NotExecuted(CMD_CLOSE(null, null), ClosingAlreadyInProgress(alice.channelId))))
     }
 
     private fun testLocalForceClose(alice: ChannelState, actions: List<ChannelAction>) {
@@ -566,7 +566,7 @@ class ShutdownTestsCommon : LightningTestSuite() {
 
         fun shutdown(alice: ChannelState, bob: ChannelState): Pair<ShuttingDown, ShuttingDown> {
             // Alice initiates a closing
-            val (alice1, actionsAlice) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+            val (alice1, actionsAlice) = alice.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
             val shutdown = actionsAlice.findOutgoingMessage<Shutdown>()
             val (bob1, actionsBob) = bob.processEx(ChannelEvent.MessageReceived(shutdown))
             val shutdown1 = actionsBob.findOutgoingMessage<Shutdown>()
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForAcceptChannelTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForAcceptChannelTestsCommon.kt
index 6689f279a..89f571635 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForAcceptChannelTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForAcceptChannelTestsCommon.kt
@@ -178,7 +178,7 @@ class WaitForAcceptChannelTestsCommon : LightningTestSuite() {
     @Test
     fun `recv CMD_CLOSE`() {
         val (alice, _, _) = init()
-        val (alice1, actions1) = alice.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice1, actions1) = alice.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice1 is Aborted)
         assertTrue(actions1.isEmpty())
     }
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingConfirmedTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingConfirmedTestsCommon.kt
index d2f51d164..739ce5e9a 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingConfirmedTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingConfirmedTestsCommon.kt
@@ -146,7 +146,7 @@ class WaitForFundingConfirmedTestsCommon : LightningTestSuite() {
     fun `recv CMD_CLOSE`() {
         val (alice, bob) = init(ChannelType.SupportedChannelType.AnchorOutputs, TestConstants.fundingAmount, TestConstants.pushMsat)
         listOf(alice, bob).forEach { state ->
-            val (state1, actions1) = state.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+            val (state1, actions1) = state.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
             assertEquals(state, state1)
             actions1.hasCommandError<CommandUnavailableInThisState>()
         }
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingCreatedTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingCreatedTestsCommon.kt
index 113c9ddb2..de269aa08 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingCreatedTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingCreatedTestsCommon.kt
@@ -62,7 +62,7 @@ class WaitForFundingCreatedTestsCommon : LightningTestSuite() {
     @Test
     fun `recv CMD_CLOSE`() {
         val (_, bob, _) = init(ChannelType.SupportedChannelType.AnchorOutputs, TestConstants.fundingAmount, TestConstants.pushMsat)
-        val (bob1, actions1) = bob.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob1, actions1) = bob.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue { bob1 is Aborted }
         assertTrue { actions1.isEmpty() }
     }
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingLockedTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingLockedTestsCommon.kt
index 4796993a9..f3c16aa4e 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingLockedTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingLockedTestsCommon.kt
@@ -80,7 +80,7 @@ class WaitForFundingLockedTestsCommon : LightningTestSuite() {
     fun `recv CMD_CLOSE`() {
         val (alice, bob, _) = init()
         listOf(alice, bob).forEach { state ->
-            val (state1, actions1) = state.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+            val (state1, actions1) = state.processEx(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
             assertEquals(state, state1)
             assertEquals(1, actions1.size)
             actions1.hasCommandError<CommandUnavailableInThisState>()
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingSignedTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingSignedTestsCommon.kt
index 308d4867c..5fc9963de 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingSignedTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForFundingSignedTestsCommon.kt
@@ -62,7 +62,7 @@ class WaitForFundingSignedTestsCommon : LightningTestSuite() {
     @Test
     fun `recv CMD_CLOSE`() {
         val (alice, _, _) = init()
-        val (alice1, actions1) = alice.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (alice1, actions1) = alice.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue(alice1 is Aborted)
         assertNull(actions1.findOutgoingMessageOpt<Error>())
     }
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForOpenChannelTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForOpenChannelTestsCommon.kt
index bb0ca6081..0625f1913 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForOpenChannelTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/channel/states/WaitForOpenChannelTestsCommon.kt
@@ -242,7 +242,7 @@ class WaitForOpenChannelTestsCommon : LightningTestSuite() {
     @Test
     fun `recv CMD_CLOSE`() {
         val (_, bob, _) = TestsHelper.init()
-        val (bob1, actions) = bob.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null)))
+        val (bob1, actions) = bob.process(ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null)))
         assertTrue { bob1 is Aborted }
         assertTrue { actions.isEmpty() }
     }
diff --git a/src/commonTest/kotlin/fr/acinq/lightning/wire/LightningCodecsTestsCommon.kt b/src/commonTest/kotlin/fr/acinq/lightning/wire/LightningCodecsTestsCommon.kt
index 88cce6392..00eb962c5 100644
--- a/src/commonTest/kotlin/fr/acinq/lightning/wire/LightningCodecsTestsCommon.kt
+++ b/src/commonTest/kotlin/fr/acinq/lightning/wire/LightningCodecsTestsCommon.kt
@@ -579,6 +579,54 @@ class LightningCodecsTestsCommon : LightningTestSuite() {
         }
     }
 
+    @Test
+    fun `encode - decode closing_signed`() {
+        val defaultSig = ByteVector64("01010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101")
+        val testCases = listOf(
+            Hex.decode("0027 0100000000000000000000000000000000000000000000000000000000000000 0000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000") to ClosingSigned(
+                ByteVector32.One,
+                0.sat,
+                ByteVector64.Zeroes
+            ),
+            Hex.decode("0027 0100000000000000000000000000000000000000000000000000000000000000 00000000000003e8 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000") to ClosingSigned(
+                ByteVector32.One,
+                1000.sat,
+                ByteVector64.Zeroes
+            ),
+            Hex.decode("0027 0100000000000000000000000000000000000000000000000000000000000000 00000000000005dc 01010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101") to ClosingSigned(
+                ByteVector32.One,
+                1500.sat,
+                defaultSig
+            ),
+            Hex.decode("0027 0100000000000000000000000000000000000000000000000000000000000000 00000000000005dc 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 0110000000000000006400000000000007d0") to ClosingSigned(
+                ByteVector32.One,
+                1500.sat,
+                ByteVector64.Zeroes,
+                TlvStream(listOf(ClosingSignedTlv.FeeRange(100.sat, 2000.sat)))
+            ),
+            Hex.decode("0027 0100000000000000000000000000000000000000000000000000000000000000 00000000000003e8 01010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101 0110000000000000006400000000000007d0") to ClosingSigned(
+                ByteVector32.One,
+                1000.sat,
+                defaultSig,
+                TlvStream(listOf(ClosingSignedTlv.FeeRange(100.sat, 2000.sat)))
+            ),
+            Hex.decode("0027 0100000000000000000000000000000000000000000000000000000000000000 0000000000000064 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 0110000000000000006400000000000003e8 030401020304") to ClosingSigned(
+                ByteVector32.One,
+                100.sat,
+                ByteVector64.Zeroes,
+                TlvStream(listOf(ClosingSignedTlv.FeeRange(100.sat, 1000.sat)), listOf(GenericTlv(3, ByteVector("01020304"))))
+            ),
+        )
+
+        testCases.forEach {
+            val decoded = LightningMessage.decode(it.first)
+            assertNotNull(decoded)
+            assertEquals(decoded, it.second)
+            val reEncoded = LightningMessage.encode(decoded)
+            assertArrayEquals(reEncoded, it.first)
+        }
+    }
+
     @Test
     fun `nonreg backup channel data`() {
         val channelId = randomBytes32()
@@ -625,11 +673,11 @@ class LightningCodecsTestsCommon : LightningTestSuite() {
             Hex.decode("0026") + channelId.toByteArray() + Hex.decode("002a") + randomData + Hex.decode("01 02 0102") + Hex.decode("fe47010000 07 cccccccccccccc") to Shutdown(channelId, randomData.toByteVector(), TlvStream(listOf(ShutdownTlv.ChannelData(EncryptedChannelData(ByteVector("cccccccccccccc")))), listOf(GenericTlv(1, ByteVector("0102"))))),
 
             Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() to ClosingSigned(channelId, 123456789.sat, signature),
-            Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("01 02 0102") to ClosingSigned(channelId, 123456789.sat, signature, TlvStream(listOf(), listOf(GenericTlv(1, ByteVector("0102"))))),
+            Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("03 02 0102") to ClosingSigned(channelId, 123456789.sat, signature, TlvStream(listOf(), listOf(GenericTlv(3, ByteVector("0102"))))),
             Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("fe47010000 00") to ClosingSigned(channelId, 123456789.sat, signature, TlvStream(listOf(ClosingSignedTlv.ChannelData(EncryptedChannelData.empty)))),
-            Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("01 02 0102") + Hex.decode("fe47010000 00") to ClosingSigned(channelId, 123456789.sat, signature, TlvStream(listOf(ClosingSignedTlv.ChannelData(EncryptedChannelData.empty)), listOf(GenericTlv(1, ByteVector("0102"))))),
+            Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("03 02 0102") + Hex.decode("fe47010000 00") to ClosingSigned(channelId, 123456789.sat, signature, TlvStream(listOf(ClosingSignedTlv.ChannelData(EncryptedChannelData.empty)), listOf(GenericTlv(3, ByteVector("0102"))))),
             Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("fe47010000 07 cccccccccccccc") to ClosingSigned(channelId, 123456789.sat, signature).withChannelData(ByteVector("cccccccccccccc")),
-            Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("01 02 0102") + Hex.decode("fe47010000 07 cccccccccccccc") to ClosingSigned(channelId, 123456789.sat, signature, TlvStream(listOf(ClosingSignedTlv.ChannelData(EncryptedChannelData(ByteVector("cccccccccccccc")))), listOf(GenericTlv(1, ByteVector("0102")))))
+            Hex.decode("0027") + channelId.toByteArray() + Hex.decode("00000000075bcd15") + signature.toByteArray() + Hex.decode("03 02 0102") + Hex.decode("fe47010000 07 cccccccccccccc") to ClosingSigned(channelId, 123456789.sat, signature, TlvStream(listOf(ClosingSignedTlv.ChannelData(EncryptedChannelData(ByteVector("cccccccccccccc")))), listOf(GenericTlv(3, ByteVector("0102")))))
         )
         // @formatter:on
 
diff --git a/src/jvmTest/kotlin/fr/acinq/lightning/Node.kt b/src/jvmTest/kotlin/fr/acinq/lightning/Node.kt
index 2434617c0..cc85a0788 100644
--- a/src/jvmTest/kotlin/fr/acinq/lightning/Node.kt
+++ b/src/jvmTest/kotlin/fr/acinq/lightning/Node.kt
@@ -264,7 +264,7 @@ object Node {
                     }
                     post("/channels/{channelId}/close") {
                         val channelId = ByteVector32(call.parameters["channelId"] ?: error("channelId not provided"))
-                        peer.send(WrappedChannelEvent(channelId, ChannelEvent.ExecuteCommand(CMD_CLOSE(null))))
+                        peer.send(WrappedChannelEvent(channelId, ChannelEvent.ExecuteCommand(CMD_CLOSE(null, null))))
                         call.respond(CloseChannelResponse("pending"))
                     }
                 }