diff --git a/packages/vats/tools/fake-bridge.js b/packages/vats/tools/fake-bridge.js
index d8e1585d6a7..8f548418aa4 100644
--- a/packages/vats/tools/fake-bridge.js
+++ b/packages/vats/tools/fake-bridge.js
@@ -291,9 +291,14 @@ export const fakeLocalChainBridgeQueryHandler = message => {
 /**
  * @param {import('@agoric/zone').Zone} zone
  * @param {(obj) => void} [onToBridge]
+ * @param {(number) => string} [makeAddressFn]
  * @returns {ScopedBridgeManager<'vlocalchain'>}
  */
-export const makeFakeLocalchainBridge = (zone, onToBridge = () => {}) => {
+export const makeFakeLocalchainBridge = (
+  zone,
+  onToBridge = () => {},
+  makeAddressFn,
+) => {
   /** @type {Remote<BridgeHandler>} */
   let hndlr;
   let lcaExecuteTxSequence = 0;
@@ -306,7 +311,9 @@ export const makeFakeLocalchainBridge = (zone, onToBridge = () => {}) => {
       trace('toBridge', type, method, params);
       switch (type) {
         case 'VLOCALCHAIN_ALLOCATE_ADDRESS': {
-          const address = `${LOCALCHAIN_DEFAULT_ADDRESS}${accountsCreated || ''}`;
+          const address = makeAddressFn
+            ? makeAddressFn(accountsCreated)
+            : `${LOCALCHAIN_DEFAULT_ADDRESS}${accountsCreated || ''}`;
           accountsCreated += 1;
           return address;
         }