diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8e7ff94dc07..95c129cb08b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -43,6 +43,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### API Breaking
  
+* (testing( [\#813](https://github.com/cosmos/ibc-go/pull/813) The `ack` argument to the testing function `RelayPacket` has been removed as it is no longer needed.
 * (testing) [\#774](https://github.com/cosmos/ibc-go/pull/774) Added `ChainID` arg to `SetupWithGenesisValSet` on the testing app. `Coordinator` generated ChainIDs now starts at index 1
 * (transfer) [\#675](https://github.com/cosmos/ibc-go/pull/675) Transfer `NewKeeper` now takes in an ICS4Wrapper. The ICS4Wrapper may be the IBC Channel Keeper when ICS20 is not used in a middleware stack. The ICS4Wrapper is required for applications wishing to connect middleware to ICS20.
 * (core) [\#650](https://github.com/cosmos/ibc-go/pull/650) Modify `OnChanOpenTry` IBC application module callback to return the negotiated app version. The version passed into the `MsgChanOpenTry` has been deprecated and will be ignored by core IBC.
diff --git a/modules/apps/27-interchain-accounts/host/ibc_module_test.go b/modules/apps/27-interchain-accounts/host/ibc_module_test.go
index d87d5dda0cb..4fec04259fd 100644
--- a/modules/apps/27-interchain-accounts/host/ibc_module_test.go
+++ b/modules/apps/27-interchain-accounts/host/ibc_module_test.go
@@ -647,8 +647,7 @@ func (suite *InterchainAccountsTestSuite) TestControlAccountAfterChannelClose()
 
 	// relay the packet
 	packetRelay := channeltypes.NewPacket(icaPacketData.GetBytes(), 1, path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, path.EndpointB.ChannelConfig.PortID, path.EndpointB.ChannelID, clienttypes.ZeroHeight(), ^uint64(0))
-	ack := channeltypes.NewResultAcknowledgement([]byte{byte(1)})
-	err = path.RelayPacket(packetRelay, ack.Acknowledgement())
+	err = path.RelayPacket(packetRelay)
 	suite.Require().NoError(err) // relay committed
 
 	// check that the ica balance is updated
@@ -679,8 +678,7 @@ func (suite *InterchainAccountsTestSuite) TestControlAccountAfterChannelClose()
 
 	// relay the packet
 	packetRelay = channeltypes.NewPacket(icaPacketData.GetBytes(), 1, path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, path.EndpointB.ChannelConfig.PortID, path.EndpointB.ChannelID, clienttypes.ZeroHeight(), ^uint64(0))
-	ack = channeltypes.NewResultAcknowledgement([]byte{byte(1)})
-	err = path.RelayPacket(packetRelay, ack.Acknowledgement())
+	err = path.RelayPacket(packetRelay)
 	suite.Require().NoError(err) // relay committed
 
 	// check that the ica balance is updated
diff --git a/modules/apps/transfer/keeper/relay_test.go b/modules/apps/transfer/keeper/relay_test.go
index be8627cc399..8e77c73db9e 100644
--- a/modules/apps/transfer/keeper/relay_test.go
+++ b/modules/apps/transfer/keeper/relay_test.go
@@ -192,8 +192,7 @@ func (suite *KeeperTestSuite) TestOnRecvPacket() {
 				// relay send packet
 				fungibleTokenPacket := types.NewFungibleTokenPacketData(coinFromBToA.Denom, coinFromBToA.Amount.String(), suite.chainB.SenderAccount.GetAddress().String(), suite.chainA.SenderAccount.GetAddress().String())
 				packet := channeltypes.NewPacket(fungibleTokenPacket.GetBytes(), 1, path.EndpointB.ChannelConfig.PortID, path.EndpointB.ChannelID, path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, clienttypes.NewHeight(0, 110), 0)
-				ack := channeltypes.NewResultAcknowledgement([]byte{byte(1)})
-				err = path.RelayPacket(packet, ack.Acknowledgement())
+				err = path.RelayPacket(packet)
 				suite.Require().NoError(err) // relay committed
 
 				seq++
diff --git a/modules/apps/transfer/transfer_test.go b/modules/apps/transfer/transfer_test.go
index 2703d4c0f30..ec36af78ceb 100644
--- a/modules/apps/transfer/transfer_test.go
+++ b/modules/apps/transfer/transfer_test.go
@@ -63,8 +63,7 @@ func (suite *TransferTestSuite) TestHandleMsgTransfer() {
 	// relay send
 	fungibleTokenPacket := types.NewFungibleTokenPacketData(coinToSendToB.Denom, coinToSendToB.Amount.String(), suite.chainA.SenderAccount.GetAddress().String(), suite.chainB.SenderAccount.GetAddress().String())
 	packet := channeltypes.NewPacket(fungibleTokenPacket.GetBytes(), 1, path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, path.EndpointB.ChannelConfig.PortID, path.EndpointB.ChannelID, timeoutHeight, 0)
-	ack := channeltypes.NewResultAcknowledgement([]byte{byte(1)})
-	err = path.RelayPacket(packet, ack.Acknowledgement())
+	err = path.RelayPacket(packet)
 	suite.Require().NoError(err) // relay committed
 
 	// check that voucher exists on chain B
@@ -92,7 +91,7 @@ func (suite *TransferTestSuite) TestHandleMsgTransfer() {
 	fullDenomPath := types.GetPrefixedDenom(pathBtoC.EndpointB.ChannelConfig.PortID, pathBtoC.EndpointB.ChannelID, voucherDenomTrace.GetFullDenomPath())
 	fungibleTokenPacket = types.NewFungibleTokenPacketData(voucherDenomTrace.GetFullDenomPath(), coinSentFromAToB.Amount.String(), suite.chainB.SenderAccount.GetAddress().String(), suite.chainC.SenderAccount.GetAddress().String())
 	packet = channeltypes.NewPacket(fungibleTokenPacket.GetBytes(), 1, pathBtoC.EndpointA.ChannelConfig.PortID, pathBtoC.EndpointA.ChannelID, pathBtoC.EndpointB.ChannelConfig.PortID, pathBtoC.EndpointB.ChannelID, timeoutHeight, 0)
-	err = pathBtoC.RelayPacket(packet, ack.Acknowledgement())
+	err = pathBtoC.RelayPacket(packet)
 	suite.Require().NoError(err) // relay committed
 
 	coinSentFromBToC := sdk.NewCoin(types.ParseDenomTrace(fullDenomPath).IBCDenom(), amount)
@@ -115,7 +114,7 @@ func (suite *TransferTestSuite) TestHandleMsgTransfer() {
 	// NOTE: fungible token is prefixed with the full trace in order to verify the packet commitment
 	fungibleTokenPacket = types.NewFungibleTokenPacketData(fullDenomPath, coinSentFromBToC.Amount.String(), suite.chainC.SenderAccount.GetAddress().String(), suite.chainB.SenderAccount.GetAddress().String())
 	packet = channeltypes.NewPacket(fungibleTokenPacket.GetBytes(), 1, pathBtoC.EndpointB.ChannelConfig.PortID, pathBtoC.EndpointB.ChannelID, pathBtoC.EndpointA.ChannelConfig.PortID, pathBtoC.EndpointA.ChannelID, timeoutHeight, 0)
-	err = pathBtoC.RelayPacket(packet, ack.Acknowledgement())
+	err = pathBtoC.RelayPacket(packet)
 	suite.Require().NoError(err) // relay committed
 
 	balance = suite.chainB.GetSimApp().BankKeeper.GetBalance(suite.chainB.GetContext(), suite.chainB.SenderAccount.GetAddress(), coinSentFromAToB.Denom)
diff --git a/testing/path.go b/testing/path.go
index f60faeaa051..d447102c7b9 100644
--- a/testing/path.go
+++ b/testing/path.go
@@ -38,7 +38,7 @@ func (path *Path) SetChannelOrdered() {
 // RelayPacket attempts to relay the packet first on EndpointA and then on EndpointB
 // if EndpointA does not contain a packet commitment for that packet. An error is returned
 // if a relay step fails or the packet commitment does not exist on either endpoint.
-func (path *Path) RelayPacket(packet channeltypes.Packet, _ []byte) error {
+func (path *Path) RelayPacket(packet channeltypes.Packet) error {
 	pc := path.EndpointA.Chain.App.GetIBCKeeper().ChannelKeeper.GetPacketCommitment(path.EndpointA.Chain.GetContext(), packet.GetSourcePort(), packet.GetSourceChannel(), packet.GetSequence())
 	if bytes.Equal(pc, channeltypes.CommitPacket(path.EndpointA.Chain.App.AppCodec(), packet)) {