diff --git a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Byron/Mempool.hs b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Byron/Mempool.hs
index ca7b93fe144..c5a034f3415 100644
--- a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Byron/Mempool.hs
+++ b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Byron/Mempool.hs
@@ -106,12 +106,6 @@ instance ApplyTx ByronBlock where
     where
       validationMode = CC.ValidationMode CC.NoBlockValidation Utxo.TxValidationNoCrypto
 
-  reapplyTxSameState cfg tx st =
-      validationErrorImpossible $
-        applyByronGenTx validationMode cfg tx st
-    where
-      validationMode = CC.ValidationMode CC.NoBlockValidation Utxo.NoTxValidation
-
 instance HasTxId (GenTx ByronBlock) where
   data TxId (GenTx ByronBlock)
     = ByronTxId             !Utxo.TxId
diff --git a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/ByronSpec/Mempool.hs b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/ByronSpec/Mempool.hs
index 318565c74dd..d2c8630fc19 100644
--- a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/ByronSpec/Mempool.hs
+++ b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/ByronSpec/Mempool.hs
@@ -50,11 +50,4 @@ instance ApplyTx ByronSpecBlock where
           (byronSpecLedgerState    st)
 
   -- Byron spec doesn't have multiple validation modes
-
-  reapplyTx          cfg tx =                   applyTx cfg tx
-  reapplyTxSameState cfg tx = dontExpectError . applyTx cfg tx
-    where
-      dontExpectError :: Except a b -> b
-      dontExpectError mb = case runExcept mb of
-        Left  _ -> error "reapplyTxSameState: unexpected error"
-        Right b -> b
+  reapplyTx = applyTx
diff --git a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Dual.hs b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Dual.hs
index 7e6b4024a26..26ee9c783fd 100644
--- a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Dual.hs
+++ b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Dual.hs
@@ -443,25 +443,6 @@ instance Bridge m a => ApplyTx (DualBlock m a) where
                                     dualLedgerStateBridge
         }
 
-  reapplyTxSameState DualLedgerConfig{..}
-                     tx@DualGenTx{..}
-                     (TickedLedgerState slot DualLedgerState{..}) =
-    TickedLedgerState slot DualLedgerState {
-        dualLedgerStateMain   = tickedLedgerState $
-                                  reapplyTxSameState
-                                    dualLedgerConfigMain
-                                    dualGenTxMain
-                                    (TickedLedgerState slot dualLedgerStateMain)
-      , dualLedgerStateAux    = tickedLedgerState $
-                                  reapplyTxSameState
-                                    dualLedgerConfigAux
-                                    dualGenTxAux
-                                    (TickedLedgerState slot dualLedgerStateAux)
-      , dualLedgerStateBridge = updateBridgeWithTx
-                                  tx
-                                  dualLedgerStateBridge
-      }
-
 instance Bridge m a => HasTxId (GenTx (DualBlock m a)) where
   -- We don't need a pair of IDs, as long as we can unique ID the transaction
   newtype TxId (GenTx (DualBlock m a)) = DualGenTxId {
diff --git a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Mock/Block.hs b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Mock/Block.hs
index 73c5315be8e..f7381c36aaa 100644
--- a/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Mock/Block.hs
+++ b/ouroboros-consensus/src/Ouroboros/Consensus/Ledger/Mock/Block.hs
@@ -284,12 +284,8 @@ instance (SimpleCrypto c, Typeable ext, SupportedBlock (SimpleBlock c ext))
 
   type ApplyTxErr (SimpleBlock c ext) = MockError (SimpleBlock c ext)
 
-  applyTx            = \_ -> updateSimpleUTxO
-  reapplyTx          = \_ -> updateSimpleUTxO
-  reapplyTxSameState = \_ -> (mustSucceed . runExcept) .: updateSimpleUTxO
-    where
-      mustSucceed (Left  _)  = error "reapplyTxSameState: unexpected error"
-      mustSucceed (Right st) = st
+  applyTx   = const updateSimpleUTxO
+  reapplyTx = const updateSimpleUTxO
 
 instance HasTxId (GenTx (SimpleBlock c ext)) where
   newtype TxId (GenTx (SimpleBlock c ext)) = SimpleGenTxId
diff --git a/ouroboros-consensus/src/Ouroboros/Consensus/Mempool/API.hs b/ouroboros-consensus/src/Ouroboros/Consensus/Mempool/API.hs
index f6bdb45e8ab..028fd24e959 100644
--- a/ouroboros-consensus/src/Ouroboros/Consensus/Mempool/API.hs
+++ b/ouroboros-consensus/src/Ouroboros/Consensus/Mempool/API.hs
@@ -69,17 +69,6 @@ class ( UpdateLedger blk
             -> TickedLedgerState blk
             -> Except (ApplyTxErr blk) (TickedLedgerState blk)
 
-  -- | Re-apply a transaction to the very same state it was applied in before
-  --
-  -- In this case no error can occur.
-  --
-  -- See also 'ldbConfReapply' for comments on implementing this function.
-  reapplyTxSameState :: HasCallStack
-                     => LedgerConfig blk
-                     -> GenTx blk
-                     -> TickedLedgerState blk
-                     -> TickedLedgerState blk
-
 -- | Transactions with an identifier
 --
 -- The mempool will use these to locate transactions, so two different