diff --git a/deploy/TokenGatewayDeploy.sol b/deploy/TokenGatewayDeploy.sol
index 3514b1d..cff3e3e 100644
--- a/deploy/TokenGatewayDeploy.sol
+++ b/deploy/TokenGatewayDeploy.sol
@@ -29,10 +29,9 @@ library TokenGatewayDeploy {
         address owner,
         address l2Gateway,
         address l1Router,
-        address inbox,
-        address escrow
+        address inbox
     ) internal returns (address l1Gateway) {
-        l1Gateway = address(new L1TokenGateway(l2Gateway, l1Router, inbox, escrow));
+        l1Gateway = address(new L1TokenGateway(l2Gateway, l1Router, inbox));
         ScriptTools.switchOwner(l1Gateway, deployer, owner);
     }
 
diff --git a/deploy/TokenGatewayInit.sol b/deploy/TokenGatewayInit.sol
index cbe5ac8..98af03a 100644
--- a/deploy/TokenGatewayInit.sol
+++ b/deploy/TokenGatewayInit.sol
@@ -27,7 +27,8 @@ interface L1TokenGatewayLike {
     function l1Router() external view returns (address);
     function inbox() external view returns (address);
     function escrow() external view returns (address);
-    function registerToken(address l1Token, address l2Token) external;
+    function file(bytes32, address) external;
+    function registerToken(address, address) external;
 }
 
 interface L1RelayLike {
@@ -80,7 +81,6 @@ library TokenGatewayInit {
         require(l1Gateway.counterpartGateway() == l2GatewayInstance.gateway, "TokenGatewayInit/counterpart-gateway-mismatch");
         require(l1Gateway.l1Router() == cfg.l1Router, "TokenGatewayInit/l1-router-mismatch");
         require(l1Gateway.inbox() == cfg.inbox, "TokenGatewayInit/inbox-mismatch");
-        require(l1Gateway.escrow() == address(escrow), "TokenGatewayInit/incorrect-escrow");
         require(cfg.l1Tokens.length == cfg.l2Tokens.length, "TokenGatewayInit/token-arrays-mismatch");
 
         uint256 l1CallValue = cfg.xchainMsg.maxSubmissionCost + cfg.xchainMsg.maxGas * cfg.xchainMsg.gasPriceBid;
@@ -89,6 +89,8 @@ library TokenGatewayInit {
         // but makes the eth balance requirement more explicit
         require(address(l1GovRelay).balance >= l1CallValue, "TokenGatewayInit/insufficient-relay-balance");
 
+        l1Gateway.file("escrow", address(escrow));
+
         for (uint256 i; i < cfg.l1Tokens.length; ++i) {
             (address l1Token, address l2Token) = (cfg.l1Tokens[i], cfg.l2Tokens[i]);
             require(l1Token != address(0), "TokenGatewayInit/invalid-l1-token");
diff --git a/script/Deploy.s.sol b/script/Deploy.s.sol
index 1252a78..6557e6b 100644
--- a/script/Deploy.s.sol
+++ b/script/Deploy.s.sol
@@ -146,7 +146,7 @@ contract Deploy is Script {
 
         l1Domain.selectFork();
         vm.startBroadcast(l1PrivKey);
-        address l1Gateway = TokenGatewayDeploy.deployL1Gateway(l1Deployer, owner, l2Gateway, l1Router, inbox, escrow);
+        address l1Gateway = TokenGatewayDeploy.deployL1Gateway(l1Deployer, owner, l2Gateway, l1Router, inbox);
         vm.stopBroadcast();
         address l2Router = L1RouterLike(l1Router).counterpartGateway();
 
diff --git a/src/L1TokenGateway.sol b/src/L1TokenGateway.sol
index aeb32fd..7a990fe 100644
--- a/src/L1TokenGateway.sol
+++ b/src/L1TokenGateway.sol
@@ -33,18 +33,19 @@ contract L1TokenGateway is ITokenGateway, IL1ArbitrumGateway, ICustomGateway, ER
     mapping(address => uint256) public wards;
     mapping(address => address) public l1ToL2Token;
     uint256 public isOpen = 1;
+    address public escrow;
 
     // --- immutables ---
 
     address public immutable counterpartGateway;
     address public immutable l1Router;
     address public immutable inbox;
-    address public immutable escrow;
 
     // --- events ---
 
     event Rely(address indexed usr);
     event Deny(address indexed usr);
+    event File(bytes32 indexed what, address data);
     event Closed();
     event DepositInitiated(
         address l1Token,
@@ -84,13 +85,11 @@ contract L1TokenGateway is ITokenGateway, IL1ArbitrumGateway, ICustomGateway, ER
     constructor(
         address _counterpartGateway,
         address _l1Router,
-        address _inbox,
-        address _escrow
+        address _inbox
     ) {
         counterpartGateway = _counterpartGateway;
         l1Router = _l1Router;
         inbox = _inbox;
-        escrow = _escrow;
 
         wards[msg.sender] = 1;
         emit Rely(msg.sender);
@@ -108,6 +107,13 @@ contract L1TokenGateway is ITokenGateway, IL1ArbitrumGateway, ICustomGateway, ER
         emit Deny(usr);
     }
 
+    function file(bytes32 what, address data) external auth {
+        if (what == "escrow") {
+            escrow = data;
+        } else revert("L1TokenGateway/file-unrecognized-param");
+        emit File(what, data);
+    }
+
     function close() external auth {
         isOpen = 0;
         emit Closed();
diff --git a/test/Integration.t.sol b/test/Integration.t.sol
index 5a4b9ce..d40841c 100644
--- a/test/Integration.t.sol
+++ b/test/Integration.t.sol
@@ -106,8 +106,7 @@ contract IntegrationTest is DssTest {
             owner:     PAUSE_PROXY,
             l2Gateway: address(l2Gateway), 
             l1Router:  L1_ROUTER,
-            inbox:     INBOX,
-            escrow:    ESCROW
+            inbox:     INBOX
         }));
         assertEq(address(l1Gateway), l1Gateway_);
 
diff --git a/test/L1TokenGateway.t.sol b/test/L1TokenGateway.t.sol
index 48fdac9..8a5f51d 100644
--- a/test/L1TokenGateway.t.sol
+++ b/test/L1TokenGateway.t.sol
@@ -52,7 +52,8 @@ contract L1TokenGatewayTest is DssTest {
 
     function setUp() public {
         inbox = new InboxMock();
-        gateway = new L1TokenGateway(counterpartGateway, l1Router, address(inbox), escrow);
+        gateway = new L1TokenGateway(counterpartGateway, l1Router, address(inbox));
+        gateway.file("escrow", escrow);
         l1Token = new GemMock(1_000_000 ether);
         vm.prank(escrow); l1Token.approve(address(gateway), type(uint256).max);
         gateway.registerToken(address(l1Token), address(0xf00));
@@ -61,13 +62,12 @@ contract L1TokenGatewayTest is DssTest {
     function testConstructor() public {
         vm.expectEmit(true, true, true, true);
         emit Rely(address(this));
-        L1TokenGateway g = new L1TokenGateway(address(111), address(222), address(333), address(444));
+        L1TokenGateway g = new L1TokenGateway(address(111), address(222), address(333));
 
         assertEq(g.isOpen(), 1);
         assertEq(g.counterpartGateway(), address(111));
         assertEq(g.l1Router(), address(222));
         assertEq(g.inbox(), address(333));
-        assertEq(g.escrow(), address(444));
         assertEq(g.wards(address(this)), 1);
     }
 
@@ -84,6 +84,10 @@ contract L1TokenGatewayTest is DssTest {
         ]);
     }
 
+    function testFileAddress() public {
+        checkFileAddress(address(gateway), "L1TokenGateway", ["escrow"]);
+    }
+
     function testErc165() public view {
         assertEq(gateway.supportsInterface(gateway.supportsInterface.selector), true);
         assertEq(gateway.supportsInterface(gateway.outboundTransferCustomRefund.selector), true);