diff --git a/contracts/evm/contracts/adapters/ClusterConnection.sol b/contracts/evm/contracts/adapters/ClusterConnection.sol
index 9dc65c5e..69efae42 100644
--- a/contracts/evm/contracts/adapters/ClusterConnection.sol
+++ b/contracts/evm/contracts/adapters/ClusterConnection.sol
@@ -10,12 +10,18 @@ import "@xcall/contracts/xcall/interfaces/IConnection.sol";
 import "@iconfoundation/xcall-solidity-library/interfaces/ICallService.sol";
 import "@iconfoundation/xcall-solidity-library/utils/RLPEncode.sol";
 import "@iconfoundation/xcall-solidity-library/utils/RLPEncode.sol";
+import "@iconfoundation/xcall-solidity-library/utils/Strings.sol";
+import "@iconfoundation/xcall-solidity-library/utils/Integers.sol";
 
+/// @custom:oz-upgrades-from contracts/adapters/ClusterConnectionV1.sol:ClusterConnectionV1
 contract ClusterConnection is Initializable, IConnection {
     using RLPEncode for bytes;
     using RLPEncode for string;
     using RLPEncode for uint256;
 
+    using Strings for bytes;
+    using Integers for uint256;
+
     mapping(string => uint256) private messageFees;
     mapping(string => uint256) private responseFees;
     mapping(string => mapping(uint256 => bool)) receipts;
@@ -312,15 +318,14 @@ contract ClusterConnection is Initializable, IConnection {
         bytes calldata _msg,
         string memory dstNetwork
     ) internal pure returns (bytes32) {
-        bytes memory rlp = abi
+        bytes memory encoded = abi
             .encodePacked(
-                srcNetwork.encodeString(),
-                _connSn.encodeUint(),
-                _msg.encodeBytes(),
-                dstNetwork.encodeString()
-            )
-            .encodeList();
-        return keccak256(rlp);
+                srcNetwork,
+                _connSn.toString(),
+                _msg.bytesToHex(),
+                dstNetwork
+            );
+        return keccak256(encoded);
     }
 
     function publicKeyToAddress(
diff --git a/contracts/evm/library/xcall/utils/Strings.sol b/contracts/evm/library/xcall/utils/Strings.sol
index 0e86716e..3ac7020b 100644
--- a/contracts/evm/library/xcall/utils/Strings.sol
+++ b/contracts/evm/library/xcall/utils/Strings.sol
@@ -47,7 +47,7 @@ library Strings {
             converted[i * 2 + 1] = _base[uint8(buffer[i]) & 0xf];
         }
 
-        return string(abi.encodePacked("0x", converted));
+        return string(converted);
     }
 
     /**
diff --git a/contracts/evm/test/adapters/ClusterConnection.t.sol b/contracts/evm/test/adapters/ClusterConnection.t.sol
index b459b367..e301a8b2 100644
--- a/contracts/evm/test/adapters/ClusterConnection.t.sol
+++ b/contracts/evm/test/adapters/ClusterConnection.t.sol
@@ -8,7 +8,8 @@ import "@xcall/contracts/xcall/CallService.sol";
 import "@xcall/contracts/mocks/multi-protocol-dapp/MultiProtocolSampleDapp.sol";
 import "@xcall/utils/Types.sol";
 import "@iconfoundation/xcall-solidity-library/utils/RLPEncode.sol";
-
+import "@iconfoundation/xcall-solidity-library/utils/Strings.sol";
+import "@iconfoundation/xcall-solidity-library/utils/Integers.sol";
 contract ClusterConnectionTest is Test {
     using RLPEncode for bytes;
     using RLPEncode for string;
@@ -16,6 +17,9 @@ contract ClusterConnectionTest is Test {
     using RLPEncodeStruct for Types.CSMessage;
     using RLPEncodeStruct for Types.CSMessageRequestV2;
 
+    using Strings for bytes;
+    using Integers for uint256;
+
     event CallExecuted(uint256 indexed _reqId, int _code, string _msg);
 
     event RollbackExecuted(uint256 indexed _sn);
@@ -393,14 +397,13 @@ contract ClusterConnectionTest is Test {
         bytes memory _msg,
         string memory dstNetwork
     ) internal pure returns (bytes32) {
-        bytes memory rlp = abi
+        bytes memory encoded = abi
             .encodePacked(
-                srcNetwork.encodeString(),
-                _connSn.encodeUint(),
-                _msg.encodeBytes(),
-                dstNetwork.encodeString()
-            )
-            .encodeList();
-        return keccak256(rlp);
+                srcNetwork,
+                _connSn.toString(),
+                _msg.bytesToHex(),
+                dstNetwork
+            );
+        return keccak256(encoded);
     }
-}
+}
\ No newline at end of file