diff --git a/packages/zoe/exported.js b/packages/zoe/exported.js
index 03fb20ed65f..e3828978f72 100644
--- a/packages/zoe/exported.js
+++ b/packages/zoe/exported.js
@@ -1,10 +1,10 @@
 // @jessie-check
 
 import './src/contractFacet/types-ambient.js';
-import './src/zoeService/types.js';
-import './src/contractSupport/types.js';
+import './src/zoeService/types-ambient.js';
+import './src/contractSupport/types-ambient.js';
 import './src/contracts/exported.js';
-import './src/types.js';
+import './src/types-ambient.js';
 import './tools/types-ambient.js';
 import '@agoric/notifier/exported.js';
 import '@agoric/ertp/exported.js';
diff --git a/packages/zoe/src/contractSupport/ratio.js b/packages/zoe/src/contractSupport/ratio.js
index f01f259941b..c4659aa968b 100644
--- a/packages/zoe/src/contractSupport/ratio.js
+++ b/packages/zoe/src/contractSupport/ratio.js
@@ -1,4 +1,4 @@
-/// <reference path="./types.js" />
+/// <reference path="./types-ambient.js" />
 import { q, Fail } from '@agoric/assert';
 import { AmountMath } from '@agoric/ertp';
 import { assertRecord } from '@endo/marshal';
diff --git a/packages/zoe/src/contractSupport/types.js b/packages/zoe/src/contractSupport/types-ambient.js
similarity index 100%
rename from packages/zoe/src/contractSupport/types.js
rename to packages/zoe/src/contractSupport/types-ambient.js
diff --git a/packages/zoe/src/types.js b/packages/zoe/src/types-ambient.js
similarity index 100%
rename from packages/zoe/src/types.js
rename to packages/zoe/src/types-ambient.js
diff --git a/packages/zoe/src/zoeService/originalZoeSeat.js b/packages/zoe/src/zoeService/originalZoeSeat.js
index 0187d07dcd3..97e4660851d 100644
--- a/packages/zoe/src/zoeService/originalZoeSeat.js
+++ b/packages/zoe/src/zoeService/originalZoeSeat.js
@@ -6,7 +6,7 @@ import { deeplyFulfilled } from '@endo/marshal';
 import { makePromiseKit } from '@endo/promise-kit';
 
 import { satisfiesWant } from '../contractFacet/offerSafety.js';
-import '../types.js';
+import '../types-ambient.js';
 import '../internal-types.js';
 import {
   AmountKeywordRecordShape,
diff --git a/packages/zoe/src/zoeService/types.js b/packages/zoe/src/zoeService/types-ambient.js
similarity index 100%
rename from packages/zoe/src/zoeService/types.js
rename to packages/zoe/src/zoeService/types-ambient.js
diff --git a/packages/zoe/src/zoeService/utils.d.ts b/packages/zoe/src/zoeService/utils.d.ts
index e10f2ad5308..a94b16b491b 100644
--- a/packages/zoe/src/zoeService/utils.d.ts
+++ b/packages/zoe/src/zoeService/utils.d.ts
@@ -1,8 +1,7 @@
 import type { Callable } from '@agoric/internal/src/utils.js';
 import type { VatUpgradeResults } from '@agoric/swingset-vat';
 import type { Baggage } from '@agoric/swingset-liveslots';
-
-import type { IssuerKeywordRecord, Payment } from './types.js';
+import type { Issuer } from '@agoric/ertp/exported.js';
 
 // XXX https://github.com/Agoric/agoric-sdk/issues/4565
 type SourceBundle = Record<string, any>;
@@ -71,7 +70,7 @@ export type ContractOf<S> = StartParams<S> & StartResult<S>;
 
 type StartContractInstance<C> = (
   installation: Installation<C>,
-  issuerKeywordRecord?: IssuerKeywordRecord,
+  issuerKeywordRecord?: Record<string, Issuer<any>>,
   terms?: object,
   privateArgs?: object,
 ) => Promise<{
@@ -113,7 +112,7 @@ export type StartedInstanceKit<SF> = {
  */
 export type StartInstance = <SF>(
   installation: Installation<SF> | PromiseLike<Installation<SF>>,
-  issuerKeywordRecord?: IssuerKeywordRecord,
+  issuerKeywordRecord?: Record<Keyword, Issuer<any>>,
   // 'brands' and 'issuers' need not be passed in; Zoe provides them as StandardTerms
   terms?: Omit<StartParams<SF>['terms'], 'brands' | 'issuers'>,
   privateArgs?: Parameters<SF>[1],
diff --git a/packages/zoe/src/zoeService/zoeSeat.js b/packages/zoe/src/zoeService/zoeSeat.js
index 363932fb89b..688dcbb6a52 100644
--- a/packages/zoe/src/zoeService/zoeSeat.js
+++ b/packages/zoe/src/zoeService/zoeSeat.js
@@ -6,7 +6,7 @@ import { deeplyFulfilled } from '@endo/marshal';
 import { makePromiseKit } from '@endo/promise-kit';
 
 import { satisfiesWant } from '../contractFacet/offerSafety.js';
-import '../types.js';
+import '../types-ambient.js';
 import '../internal-types.js';
 import {
   declareOldZoeSeatAdminKind,
diff --git a/packages/zoe/test/unitTests/contractSupport/test-ratio.js b/packages/zoe/test/unitTests/contractSupport/test-ratio.js
index f229f19e2a2..69a3febe1b6 100644
--- a/packages/zoe/test/unitTests/contractSupport/test-ratio.js
+++ b/packages/zoe/test/unitTests/contractSupport/test-ratio.js
@@ -1,6 +1,6 @@
 import { test } from '@agoric/swingset-vat/tools/prepare-test-env-ava.js';
 
-import '../../../src/contractSupport/types.js';
+import '../../../src/contractSupport/types-ambient.js';
 
 import { makeIssuerKit, AmountMath } from '@agoric/ertp';
 import {
diff --git a/packages/zoe/typedoc.json b/packages/zoe/typedoc.json
index e5a2997cfc2..bdab322c101 100644
--- a/packages/zoe/typedoc.json
+++ b/packages/zoe/typedoc.json
@@ -6,9 +6,9 @@
         "src/contractFacet/internal-types.js",
         "src/contractFacet/types-ambient.d.ts",
         "src/contractSupport/index.js",
-        "src/contractSupport/types.js",
+        "src/contractSupport/types-ambient.js",
         "src/types.js",
-        "src/zoeService/types.js",
+        "src/zoeService/types-ambient.js",
         "src/zoeService/utils.d.ts",
         "src/zoeService/zoe.js",
         "tools/internal-types.js",