diff --git a/packages/contracts-bedrock/scripts/L2Genesis.s.sol b/packages/contracts-bedrock/scripts/L2Genesis.s.sol
index 647e3222227d..2cd3da78226d 100644
--- a/packages/contracts-bedrock/scripts/L2Genesis.s.sol
+++ b/packages/contracts-bedrock/scripts/L2Genesis.s.sol
@@ -192,7 +192,7 @@ contract L2Genesis is Deployer {
             vm.etch(addr, code);
             EIP1967Helper.setAdmin(addr, Predeploys.PROXY_ADMIN);
 
-            if (Predeploys.isSupportedPredeploy(addr)) {
+            if (Predeploys.isSupportedPredeploy(addr, cfg.useInterop())) {
                 address implementation = Predeploys.predeployToCodeNamespace(addr);
                 console.log("Setting proxy %s implementation: %s", addr, implementation);
                 EIP1967Helper.setImplementation(addr, implementation);
@@ -231,6 +231,10 @@ contract L2Genesis is Deployer {
         setSchemaRegistry(); // 20
         setEAS(); // 21
         setGovernanceToken(); // 42: OP (not behind a proxy)
+        if (cfg.useInterop()) {
+            setCrossL2Inbox(); // 22
+            setL2ToL2CrossDomainMessenger(); // 23
+        }
     }
 
     function setProxyAdmin() public {
@@ -441,6 +445,18 @@ contract L2Genesis is Deployer {
         vm.resetNonce(address(eas));
     }
 
+    /// @notice This predeploy is following the saftey invariant #2.
+    ///         This contract has no initializer.
+    function setCrossL2Inbox() internal {
+        _setImplementationCode(Predeploys.CROSS_L2_INBOX);
+    }
+
+    /// @notice This predeploy is following the saftey invariant #2.
+    ///         This contract has no initializer.
+    function setL2ToL2CrossDomainMessenger() internal {
+        _setImplementationCode(Predeploys.L2_TO_L2_CROSS_DOMAIN_MESSENGER);
+    }
+
     /// @notice Sets all the preinstalls.
     ///         Warning: the creator-accounts of the preinstall contracts have 0 nonce values.
     ///         When performing a regular user-initiated contract-creation of a preinstall,
diff --git a/packages/contracts-bedrock/src/libraries/Predeploys.sol b/packages/contracts-bedrock/src/libraries/Predeploys.sol
index ed00c991ba5b..d37dbca6af11 100644
--- a/packages/contracts-bedrock/src/libraries/Predeploys.sol
+++ b/packages/contracts-bedrock/src/libraries/Predeploys.sol
@@ -124,13 +124,14 @@ library Predeploys {
     }
 
     /// @notice Returns true if the address is a defined predeploy that is embedded into new OP-Stack chains.
-    function isSupportedPredeploy(address _addr) internal pure returns (bool) {
+    function isSupportedPredeploy(address _addr, bool _useInterop) internal pure returns (bool) {
         return _addr == LEGACY_MESSAGE_PASSER || _addr == DEPLOYER_WHITELIST || _addr == WETH
             || _addr == L2_CROSS_DOMAIN_MESSENGER || _addr == GAS_PRICE_ORACLE || _addr == L2_STANDARD_BRIDGE
             || _addr == SEQUENCER_FEE_WALLET || _addr == OPTIMISM_MINTABLE_ERC20_FACTORY || _addr == L1_BLOCK_NUMBER
             || _addr == L2_ERC721_BRIDGE || _addr == L1_BLOCK_ATTRIBUTES || _addr == L2_TO_L1_MESSAGE_PASSER
             || _addr == OPTIMISM_MINTABLE_ERC721_FACTORY || _addr == PROXY_ADMIN || _addr == BASE_FEE_VAULT
-            || _addr == L1_FEE_VAULT || _addr == SCHEMA_REGISTRY || _addr == EAS || _addr == GOVERNANCE_TOKEN;
+            || _addr == L1_FEE_VAULT || _addr == SCHEMA_REGISTRY || _addr == EAS || _addr == GOVERNANCE_TOKEN
+            || (_useInterop && _addr == CROSS_L2_INBOX) || (_useInterop && _addr == L2_TO_L2_CROSS_DOMAIN_MESSENGER);
     }
 
     function isPredeployNamespace(address _addr) internal pure returns (bool) {
diff --git a/packages/contracts-bedrock/test/L2Genesis.t.sol b/packages/contracts-bedrock/test/L2Genesis.t.sol
index 68e0f559c074..551e01088947 100644
--- a/packages/contracts-bedrock/test/L2Genesis.t.sol
+++ b/packages/contracts-bedrock/test/L2Genesis.t.sol
@@ -121,13 +121,27 @@ contract L2GenesisTest is Test {
         return abi.decode(vm.ffi(commands), (uint256));
     }
 
-    /// @notice Tests the genesis predeploys setup using a temp file.
-    function test_genesis_predeploys() external {
-        withTempDump(_test_genesis_predeploys);
+    /// @notice Tests the genesis predeploys setup using a temp file for the case where useInterop is false.
+    function test_genesis_predeploys_notUsingInterop() external {
+        string memory path = tmpfile();
+        _test_genesis_predeploys(path, false);
+        deleteFile(path);
+    }
+
+    /// @notice Tests the genesis predeploys setup using a temp file for the case where useInterop is true.
+    function test_genesis_predeploys_usingInterop() external {
+        string memory path = tmpfile();
+        _test_genesis_predeploys(path, true);
+        deleteFile(path);
     }
 
     /// @notice Tests the genesis predeploys setup.
-    function _test_genesis_predeploys(string memory _path) internal {
+    function _test_genesis_predeploys(string memory _path, bool _useInterop) internal {
+        // Set the useInterop value
+        vm.mockCall(
+            address(genesis.cfg()), abi.encodeWithSelector(genesis.cfg().useInterop.selector), abi.encode(_useInterop)
+        );
+
         // Set the predeploy proxies into state
         genesis.setPredeployProxies();
         genesis.writeGenesisAllocs(_path);
@@ -135,8 +149,8 @@ contract L2GenesisTest is Test {
         // 2 predeploys do not have proxies
         assertEq(getCodeCount(_path, "Proxy.sol:Proxy"), Predeploys.PREDEPLOY_COUNT - 2);
 
-        // 17 proxies have the implementation set
-        assertEq(getPredeployCountWithSlotSet(_path, Constants.PROXY_IMPLEMENTATION_ADDRESS), 17);
+        // 19 proxies have the implementation set if useInterop is true and 17 if useInterop is false
+        assertEq(getPredeployCountWithSlotSet(_path, Constants.PROXY_IMPLEMENTATION_ADDRESS), _useInterop ? 19 : 17);
 
         // All proxies except 2 have the proxy 1967 admin slot set to the proxy admin
         assertEq(