diff --git a/src/CCTPBase.sol b/src/CCTPBase.sol
index 23dd5cb..7945c08 100644
--- a/src/CCTPBase.sol
+++ b/src/CCTPBase.sol
@@ -45,14 +45,14 @@ abstract contract CCTPBase is TokenBase {
         USDC = _USDC;
     }
 
-    function getCCTPDomain(uint16 targetChain) internal pure returns (uint32) {
-        if (targetChain == 2) {
+    function getCCTPDomain(uint16 chain) internal pure returns (uint32) {
+        if (chain == 2) {
             return 0;
-        } else if (targetChain == 6) {
+        } else if (chain == 6) {
             return 1;
-        } else if (targetChain == 23) {
+        } else if (chain == 23) {
             return 3;
-        } else if (targetChain == 24) {
+        } else if (chain == 24) {
             return 2;
         } else {
             revert("Wrong CCTP Domain");
@@ -95,7 +95,7 @@ abstract contract CCTPSender is CCTPBase {
             addressToBytes32CCTP(targetAddress)
         );
         return MessageKey(
-            CCTPMessageLib.CCTP_KEY_TYPE, abi.encodePacked(getCCTPDomain(targetChain), nonce)
+            CCTPMessageLib.CCTP_KEY_TYPE, abi.encodePacked(getCCTPDomain(wormhole.chainId()), nonce)
         );
     }
 
diff --git a/src/testing/helpers/MockOffchainRelayer.sol b/src/testing/helpers/MockOffchainRelayer.sol
index 6807230..6d6777e 100644
--- a/src/testing/helpers/MockOffchainRelayer.sol
+++ b/src/testing/helpers/MockOffchainRelayer.sol
@@ -104,7 +104,7 @@ contract MockOffchainRelayer {
         CCTPMessageLib.CCTPMessage memory cctpMessage
     ) internal pure returns (bool) {
         (uint64 nonce,) = cctpMessage.message.asUint64(12);
-        (uint32 domain,) = cctpMessage.message.asUint32(8);
+        (uint32 domain,) = cctpMessage.message.asUint32(4);
         return
            nonce == cctpKey.nonce && domain == cctpKey.domain;
     }