diff --git a/contracts/Dispatcher.sol b/contracts/Dispatcher.sol
index 7c3d2f58..e8c15c78 100644
--- a/contracts/Dispatcher.sol
+++ b/contracts/Dispatcher.sol
@@ -578,7 +578,7 @@ contract Dispatcher is IbcDispatcher, Ownable {
             nextSequenceAck[address(receiver)][packet.src.channelId] = packet.sequence + 1;
         }
 
-        receiver.onAcknowledgementPacket(packet);
+        receiver.onAcknowledgementPacket(packet, ackPacket);
 
         // delete packet commitment to avoid double ack
         delete sendPacketCommitment[address(receiver)][packet.src.channelId][packet.sequence];
diff --git a/contracts/IbcReceiver.sol b/contracts/IbcReceiver.sol
index ab75b7a6..cc621eb3 100644
--- a/contracts/IbcReceiver.sol
+++ b/contracts/IbcReceiver.sol
@@ -18,7 +18,7 @@ interface IbcReceiver {
 
     function onRecvPacket(IbcPacket calldata packet) external returns (AckPacket memory ackPacket);
 
-    function onAcknowledgementPacket(IbcPacket calldata packet) external;
+    function onAcknowledgementPacket(IbcPacket calldata packet, AckPacket calldata ack) external;
 
     function onTimeoutPacket(IbcPacket calldata packet) external;
 
diff --git a/contracts/Mars.sol b/contracts/Mars.sol
index 7153ad4b..3853f720 100644
--- a/contracts/Mars.sol
+++ b/contracts/Mars.sol
@@ -7,8 +7,11 @@ import './IbcReceiver.sol';
 import './IbcDispatcher.sol';
 
 contract Mars is IbcReceiver, Ownable {
+    // received packet as chain B
     IbcPacket[] public recvedPackets;
-    IbcPacket[] public ackPackets;
+    // received ack packet as chain A
+    AckPacket[] public ackPackets;
+    // received timeout packet as chain A
     IbcPacket[] public timeoutPackets;
     bytes32[] public connectedChannels;
 
@@ -19,8 +22,8 @@ contract Mars is IbcReceiver, Ownable {
         return AckPacket(true, abi.encodePacked('{ "account": "account", "reply": "got the message" }'));
     }
 
-    function onAcknowledgementPacket(IbcPacket calldata packet) external {
-        ackPackets.push(packet);
+    function onAcknowledgementPacket(IbcPacket calldata packet, AckPacket calldata ack) external {
+        ackPackets.push(ack);
     }
 
     function onTimeoutPacket(IbcPacket calldata packet) external {
diff --git a/test/Dispatcher.t.sol b/test/Dispatcher.t.sol
index 7c92a432..eb65ffc8 100644
--- a/test/Dispatcher.t.sol
+++ b/test/Dispatcher.t.sol
@@ -634,6 +634,10 @@ contract DispatcherAckPacketTest is PacketSenderTest {
             vm.expectEmit(true, true, false, true, address(dispatcher));
             emit Acknowledgement(address(mars), channelId, sentPacket.sequence);
             dispatcher.acknowledgement(IbcReceiver(mars), sentPacket, ackPacket, validProof);
+            // confirm dapp recieved the ack
+            (bool success, bytes memory data) = mars.ackPackets(sentPacket.sequence - 1);
+            assertEq(success, ackPacket.success);
+            assertEq(data, ackPacket.data);
         }
     }