diff --git a/test/invariant/MockAdaptor.sol b/test/invariant/MockAdaptor.sol
new file mode 100644
index 00000000..d774342c
--- /dev/null
+++ b/test/invariant/MockAdaptor.sol
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: Apache 2.0
+pragma solidity 0.8.19;
+
+import {Test} from "forge-std/Test.sol";
+import {IChildBridgeAdaptor} from "../../src/interfaces/child/IChildBridgeAdaptor.sol";
+import {IRootBridgeAdaptor} from "../../src/interfaces/root/IRootBridgeAdaptor.sol";
+
+interface MessageReceiver {
+    function onMessageReceive(bytes calldata data) external;
+}
+
+contract MockAdaptor is Test, IChildBridgeAdaptor, IRootBridgeAdaptor {
+
+    uint256 chainId;
+    MessageReceiver messageReceiver;
+    MockAdaptor otherAdaptor;
+
+    constructor() {}
+
+    function initialize(uint256 _chainId, address _messageReceiver, address _otherAdaptor) public {
+        chainId = _chainId;
+        messageReceiver = MessageReceiver(_messageReceiver);
+        otherAdaptor = MockAdaptor(_otherAdaptor);
+    }
+
+    function sendMessage(bytes calldata payload, address /*refundRecipient*/) external payable override(IChildBridgeAdaptor, IRootBridgeAdaptor) {
+        otherAdaptor.onMessageReceive(payload);
+        vm.selectFork(chainId);
+    }
+
+    function onMessageReceive(bytes calldata data) external {
+        vm.selectFork(chainId);
+        messageReceiver.onMessageReceive(data);
+    }
+}
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