diff --git a/CHANGELOG.md b/CHANGELOG.md
index f9d669650a3..41f73929faf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -45,6 +45,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### API Breaking
  
+* (modules/core/05-port) [\#1086](https://github.com/cosmos/ibc-go/pull/1086) Added `counterpartyChannelID` argument to IBCModule.OnChanOpenAck
 * (channel) [\#848](https://github.com/cosmos/ibc-go/pull/848) Added `ChannelId` to MsgChannelOpenInitResponse
 * (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
diff --git a/docs/migrations/v2-to-v3.md b/docs/migrations/v2-to-v3.md
index beab128a1fd..98987e78395 100644
--- a/docs/migrations/v2-to-v3.md
+++ b/docs/migrations/v2-to-v3.md
@@ -114,6 +114,10 @@ IBC applications must perform application version negoitation in `OnChanOpenTry`
 The negotiated application version then must be returned in `OnChanOpenTry` to core IBC.
 Core IBC will set this version in the TRYOPEN channel.
 
+### `OnChanOpenAck` will take additional `counterpartyChannelID` argument
+The `OnChanOpenAck` application callback has been modified.
+The arguments now include the counterparty channel id.
+
 ### `NegotiateAppVersion` removed from `IBCModule` interface
 
 Previously this logic was handled by the `NegotiateAppVersion` function.
diff --git a/modules/apps/27-interchain-accounts/controller/ibc_module.go b/modules/apps/27-interchain-accounts/controller/ibc_module.go
index 1aa362a4247..c00c9f5d1c2 100644
--- a/modules/apps/27-interchain-accounts/controller/ibc_module.go
+++ b/modules/apps/27-interchain-accounts/controller/ibc_module.go
@@ -80,6 +80,7 @@ func (im IBCModule) OnChanOpenAck(
 	ctx sdk.Context,
 	portID,
 	channelID string,
+	counterpartyChannelID string,
 	counterpartyVersion string,
 ) error {
 	if !im.keeper.IsControllerEnabled(ctx) {
@@ -91,7 +92,7 @@ func (im IBCModule) OnChanOpenAck(
 	}
 
 	// call underlying app's OnChanOpenAck callback with the counterparty app version.
-	return im.app.OnChanOpenAck(ctx, portID, channelID, counterpartyVersion)
+	return im.app.OnChanOpenAck(ctx, portID, channelID, counterpartyChannelID, counterpartyVersion)
 }
 
 // OnChanOpenAck implements the IBCModule interface
diff --git a/modules/apps/27-interchain-accounts/controller/ibc_module_test.go b/modules/apps/27-interchain-accounts/controller/ibc_module_test.go
index f2b5d36ac63..db4412d144e 100644
--- a/modules/apps/27-interchain-accounts/controller/ibc_module_test.go
+++ b/modules/apps/27-interchain-accounts/controller/ibc_module_test.go
@@ -285,7 +285,7 @@ func (suite *InterchainAccountsTestSuite) TestOnChanOpenAck() {
 		{
 			"ICA auth module callback fails", func() {
 				suite.chainA.GetSimApp().ICAAuthModule.IBCApp.OnChanOpenAck = func(
-					ctx sdk.Context, portID, channelID string, counterpartyVersion string,
+					ctx sdk.Context, portID, channelID string, counterpartyChannelID string, counterpartyVersion string,
 				) error {
 					return fmt.Errorf("mock ica auth fails")
 				}
@@ -316,7 +316,7 @@ func (suite *InterchainAccountsTestSuite) TestOnChanOpenAck() {
 			cbs, ok := suite.chainA.App.GetIBCKeeper().Router.GetRoute(module)
 			suite.Require().True(ok)
 
-			err = cbs.OnChanOpenAck(suite.chainA.GetContext(), path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, path.EndpointB.ChannelConfig.Version)
+			err = cbs.OnChanOpenAck(suite.chainA.GetContext(), path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, path.EndpointB.ChannelID, path.EndpointB.ChannelConfig.Version)
 
 			if tc.expPass {
 				suite.Require().NoError(err)
diff --git a/modules/apps/27-interchain-accounts/host/ibc_module.go b/modules/apps/27-interchain-accounts/host/ibc_module.go
index 630c4d44fc1..fb403c71937 100644
--- a/modules/apps/27-interchain-accounts/host/ibc_module.go
+++ b/modules/apps/27-interchain-accounts/host/ibc_module.go
@@ -61,6 +61,7 @@ func (im IBCModule) OnChanOpenAck(
 	ctx sdk.Context,
 	portID,
 	channelID string,
+	counterpartyChannelID string,
 	counterpartyVersion string,
 ) error {
 	return sdkerrors.Wrap(icatypes.ErrInvalidChannelFlow, "channel handshake must be initiated by controller chain")
diff --git a/modules/apps/transfer/ibc_module.go b/modules/apps/transfer/ibc_module.go
index c784a91e933..f5ed807d8b2 100644
--- a/modules/apps/transfer/ibc_module.go
+++ b/modules/apps/transfer/ibc_module.go
@@ -125,6 +125,7 @@ func (im IBCModule) OnChanOpenAck(
 	ctx sdk.Context,
 	portID,
 	channelID string,
+	_ string,
 	counterpartyVersion string,
 ) error {
 	if counterpartyVersion != types.Version {
diff --git a/modules/apps/transfer/ibc_module_test.go b/modules/apps/transfer/ibc_module_test.go
index b5f834a3a8e..92d0f30d4c7 100644
--- a/modules/apps/transfer/ibc_module_test.go
+++ b/modules/apps/transfer/ibc_module_test.go
@@ -228,7 +228,7 @@ func (suite *TransferTestSuite) TestOnChanOpenAck() {
 
 			tc.malleate() // explicitly change fields in channel and testChannel
 
-			err = cbs.OnChanOpenAck(suite.chainA.GetContext(), path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, counterpartyVersion)
+			err = cbs.OnChanOpenAck(suite.chainA.GetContext(), path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID, path.EndpointA.Counterparty.ChannelID, counterpartyVersion)
 
 			if tc.expPass {
 				suite.Require().NoError(err)
diff --git a/modules/core/05-port/types/module.go b/modules/core/05-port/types/module.go
index dea418b7250..9f754fe0a3e 100644
--- a/modules/core/05-port/types/module.go
+++ b/modules/core/05-port/types/module.go
@@ -51,6 +51,7 @@ type IBCModule interface {
 		ctx sdk.Context,
 		portID,
 		channelID string,
+		counterpartyChannelID string,
 		counterpartyVersion string,
 	) error
 
diff --git a/modules/core/keeper/msg_server.go b/modules/core/keeper/msg_server.go
index b19041f636d..a380540614c 100644
--- a/modules/core/keeper/msg_server.go
+++ b/modules/core/keeper/msg_server.go
@@ -261,7 +261,7 @@ func (k Keeper) ChannelOpenAck(goCtx context.Context, msg *channeltypes.MsgChann
 	}
 
 	// Perform application logic callback
-	if err = cbs.OnChanOpenAck(ctx, msg.PortId, msg.ChannelId, msg.CounterpartyVersion); err != nil {
+	if err = cbs.OnChanOpenAck(ctx, msg.PortId, msg.ChannelId, msg.CounterpartyChannelId, msg.CounterpartyVersion); err != nil {
 		return nil, sdkerrors.Wrap(err, "channel open ack callback failed")
 	}
 
diff --git a/testing/mock/ibc_app.go b/testing/mock/ibc_app.go
index 15f77d02d5a..77eb17b8c6f 100644
--- a/testing/mock/ibc_app.go
+++ b/testing/mock/ibc_app.go
@@ -40,6 +40,7 @@ type MockIBCApp struct {
 		ctx sdk.Context,
 		portID,
 		channelID string,
+		counterpartyChannelID string,
 		counterpartyVersion string,
 	) error
 
diff --git a/testing/mock/ibc_module.go b/testing/mock/ibc_module.go
index 1ea1d3850ad..e58f6ae7156 100644
--- a/testing/mock/ibc_module.go
+++ b/testing/mock/ibc_module.go
@@ -64,9 +64,9 @@ func (im IBCModule) OnChanOpenTry(
 }
 
 // OnChanOpenAck implements the IBCModule interface.
-func (im IBCModule) OnChanOpenAck(ctx sdk.Context, portID string, channelID string, counterpartyVersion string) error {
+func (im IBCModule) OnChanOpenAck(ctx sdk.Context, portID string, channelID string, counterpartyChannelID string, counterpartyVersion string) error {
 	if im.IBCApp.OnChanOpenAck != nil {
-		return im.IBCApp.OnChanOpenAck(ctx, portID, channelID, counterpartyVersion)
+		return im.IBCApp.OnChanOpenAck(ctx, portID, channelID, counterpartyChannelID, counterpartyVersion)
 	}
 
 	return nil