diff --git a/src/TWCloneFactory.sol b/src/TWCloneFactory.sol
index 92d24506..5dbc585b 100644
--- a/src/TWCloneFactory.sol
+++ b/src/TWCloneFactory.sol
@@ -25,7 +25,7 @@ contract TWCloneFactory {
         }
     }
 
-    function _guard(bytes32 salt, bytes memory data) internal returns (bytes32) {
+    function _guard(bytes32 salt, bytes memory data) internal view returns (bytes32) {
         // 01 if cross chain deployment is allowed
         // 00 if cross chain deployment is not allowed
         bool allowCrossChainDeployment = bytes1(salt[0]) == hex"01";
diff --git a/test/TWCloneFactory.t.sol b/test/TWCloneFactory.t.sol
new file mode 100644
index 00000000..af8c9713
--- /dev/null
+++ b/test/TWCloneFactory.t.sol
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.20;
+
+import "../src/TWCloneFactory.sol";
+import {LibClone} from "@solady/utils/LibClone.sol";
+import "forge-std/Test.sol";
+
+contract MockImplementation {
+
+    uint256 public value;
+
+    function initialize(uint256 _value) public {
+        value = _value;
+    }
+
+}
+
+contract TWCloneFactoryTest is Test {
+
+    TWCloneFactory factory;
+    MockImplementation implementation;
+
+    uint256 chainId1 = 1;
+    uint256 chainId2 = 2;
+
+    function setUp() public {
+        factory = new TWCloneFactory();
+        implementation = new MockImplementation();
+    }
+
+    // Test case 1: Cross chain deployment on - same address on two chains
+    function testCrossChainDeploymentOnSameAddress() public {
+        // Set up the salt with allowCrossChainDeployment = true, encodeDataIntoSalt = false
+        // salt[0] == hex"01", salt[1] == hex"00"
+        bytes32 salt = bytes32(abi.encodePacked(hex"01", hex"00", bytes30(0)));
+        bytes memory data = "";
+
+        // Save the current state
+        uint256 snapshotId = vm.snapshot();
+
+        // Set chain ID to chainId1 and deploy
+        vm.chainId(chainId1);
+        address proxy1 = factory.deployProxyByImplementation(address(implementation), data, salt);
+
+        // Revert to the snapshot to reset the state
+        vm.revertTo(snapshotId);
+
+        // Set chain ID to chainId2 and deploy
+        vm.chainId(chainId2);
+        address proxy2 = factory.deployProxyByImplementation(address(implementation), data, salt);
+
+        // Check that the proxies are the same
+        assertEq(proxy1, proxy2, "Proxies should be the same on different chains when cross chain deployment is on");
+    }
+
+    // Test case 2: Cross chain deployment off - different address on two chains
+    function testCrossChainDeploymentOffDifferentAddress() public {
+        // Set up the salt with allowCrossChainDeployment = false, encodeDataIntoSalt = false
+        // salt[0] == hex"00", salt[1] == hex"00"
+        bytes32 salt = bytes32(abi.encodePacked(hex"00", hex"00", bytes30(0)));
+        bytes memory data = "";
+
+        // Save the current state
+        uint256 snapshotId = vm.snapshot();
+
+        // Set chain ID to chainId1 and deploy
+        vm.chainId(chainId1);
+        address proxy1 = factory.deployProxyByImplementation(address(implementation), data, salt);
+
+        // Revert to the snapshot to reset the state
+        vm.revertTo(snapshotId);
+
+        // Set chain ID to chainId2 and deploy
+        vm.chainId(chainId2);
+        address proxy2 = factory.deployProxyByImplementation(address(implementation), data, salt);
+
+        // Check that the proxies are different
+        assertNotEq(
+            proxy1, proxy2, "Proxies should be different on different chains when cross chain deployment is off"
+        );
+    }
+
+    // Test case 3: Not encodeDataIntoSalt - same address with different init data
+    function testNotEncodeDataIntoSaltSameAddress() public {
+        // Set up the salt with allowCrossChainDeployment = true, encodeDataIntoSalt = false
+        // salt[0] == hex"01", salt[1] == hex"00"
+        bytes32 salt = bytes32(abi.encodePacked(hex"01", hex"00", bytes30(0)));
+
+        // Save the current state
+        uint256 snapshotId = vm.snapshot();
+
+        // Deploy with data1
+        vm.chainId(chainId1);
+        bytes memory data1 = abi.encodeWithSignature("initialize(uint256)", 42);
+        address proxy1 = factory.deployProxyByImplementation(address(implementation), data1, salt);
+
+        // Revert to the snapshot to reset the state
+        vm.revertTo(snapshotId);
+
+        // Deploy with data2
+        vm.chainId(chainId2);
+        bytes memory data2 = abi.encodeWithSignature("initialize(uint256)", 100);
+        address proxy2 = factory.deployProxyByImplementation(address(implementation), data2, salt);
+
+        // Check that the proxies are the same
+        assertEq(proxy1, proxy2, "Proxies should be the same when encodeDataIntoSalt is off");
+    }
+
+    // Test case 4: Encode Data into salt - different address with different init data
+    function testEncodeDataIntoSaltDifferentAddress() public {
+        // Set up the salt with allowCrossChainDeployment = true, encodeDataIntoSalt = true
+        // salt[0] == hex"01", salt[1] == hex"01"
+        bytes32 salt = bytes32(abi.encodePacked(hex"01", hex"01", bytes30(0)));
+
+        // Deploy with data1
+        bytes memory data1 = abi.encodeWithSignature("initialize(uint256)", 42);
+        address proxy1 = factory.deployProxyByImplementation(address(implementation), data1, salt);
+
+        // Deploy with data2
+        bytes memory data2 = abi.encodeWithSignature("initialize(uint256)", 100);
+        address proxy2 = factory.deployProxyByImplementation(address(implementation), data2, salt);
+
+        // Check that the proxies are different
+        assertNotEq(proxy1, proxy2, "Proxies should be different when encodeDataIntoSalt is on");
+
+        // Verify that both initializations took effect independently
+        MockImplementation proxyImpl1 = MockImplementation(proxy1);
+        uint256 value1 = proxyImpl1.value();
+        assertEq(value1, 42, "Value should be initialized to 42");
+
+        MockImplementation proxyImpl2 = MockImplementation(proxy2);
+        uint256 value2 = proxyImpl2.value();
+        assertEq(value2, 100, "Value should be initialized to 100");
+    }
+
+}