diff --git a/packages/ERTP/src/issuerKit.js b/packages/ERTP/src/issuerKit.js
index fa6b15d30441..65cce4993c5e 100644
--- a/packages/ERTP/src/issuerKit.js
+++ b/packages/ERTP/src/issuerKit.js
@@ -11,11 +11,6 @@ import { preparePaymentLedger } from './paymentLedger.js';
 
 import './types-ambient.js';
 
-// TODO Why does TypeScript lose the `MapStore` typing of `Baggage` here, even
-// though it knows the correct type at the exporting `@agoric/vat-data`
-/** @typedef {import('@agoric/vat-data').Baggage} Baggage */
-/** @typedef {import('@agoric/zone').Zone} Zone */
-
 /**
  * @template {AssetKind} K
  * @typedef {object} IssuerRecord
@@ -30,7 +25,7 @@ import './types-ambient.js';
  *
  * @template {AssetKind} K
  * @param {IssuerRecord<K>} issuerRecord
- * @param {Zone} issuerZone
+ * @param {import('@agoric/zone').Zone} issuerZone
  * @param {ShutdownWithFailure} [optShutdownWithFailure] If this issuer fails in
  *   the middle of an atomic action (which btw should never happen), it
  *   potentially leaves its ledger in a corrupted state. If this function was
@@ -88,7 +83,7 @@ const INSTANCE_KEY = 'issuer';
  * make a new one.
  *
  * @template {AssetKind} K
- * @param {Baggage} issuerBaggage
+ * @param {import('@agoric/vat-data').Baggage} issuerBaggage
  * @param {ShutdownWithFailure} [optShutdownWithFailure] If this issuer fails in
  *   the middle of an atomic action (which btw should never happen), it
  *   potentially leaves its ledger in a corrupted state. If this function was
@@ -111,7 +106,7 @@ harden(upgradeIssuerKit);
 /**
  * Does baggage already have an issuerKit?
  *
- * @param {Baggage} baggage
+ * @param {import('@agoric/vat-data').Baggage} baggage
  */
 export const hasIssuer = baggage => baggage.has(INSTANCE_KEY);
 
@@ -145,7 +140,7 @@ export const hasIssuer = baggage => baggage.has(INSTANCE_KEY);
  *   basic fungible tokens.
  *
  *   `displayInfo` gives information to the UI on how to display the amount.
- * @param {Baggage} issuerBaggage
+ * @param {import('@agoric/vat-data').Baggage} issuerBaggage
  * @param {string} name
  * @param {K} [assetKind]
  * @param {AdditionalDisplayInfo} [displayInfo]
@@ -191,7 +186,7 @@ harden(makeDurableIssuerKit);
  *   basic fungible tokens.
  *
  *   `displayInfo` gives information to the UI on how to display the amount.
- * @param {Baggage} issuerBaggage
+ * @param {import('@agoric/vat-data').Baggage} issuerBaggage
  * @param {string} name
  * @param {K} [assetKind]
  * @param {AdditionalDisplayInfo} [displayInfo]
diff --git a/packages/ERTP/src/mathHelpers/copyBagMathHelpers.js b/packages/ERTP/src/mathHelpers/copyBagMathHelpers.js
index 20305c246100..10ae707124bd 100644
--- a/packages/ERTP/src/mathHelpers/copyBagMathHelpers.js
+++ b/packages/ERTP/src/mathHelpers/copyBagMathHelpers.js
@@ -12,10 +12,10 @@ import {
 } from '@agoric/store';
 import '../types-ambient.js';
 
-/** @type {CopyBag} */
+/** @type {import('@endo/patterns').CopyBag} */
 const empty = makeCopyBag([]);
 
-/** @type {MathHelpers<CopyBag>} */
+/** @type {MathHelpers<import('@endo/patterns').CopyBag>} */
 export const copyBagMathHelpers = harden({
   doCoerce: bag => {
     mustMatch(bag, M.bag(), 'bag of amount');
diff --git a/packages/ERTP/src/payment.js b/packages/ERTP/src/payment.js
index 499151966f82..2bc61cab4aab 100644
--- a/packages/ERTP/src/payment.js
+++ b/packages/ERTP/src/payment.js
@@ -2,19 +2,13 @@
 
 import { initEmpty } from '@agoric/store';
 
-/** @typedef {import('@endo/patterns').MethodGuard} MethodGuard */
-/**
- * @template {Record<string | symbol, MethodGuard>} [T=Record<string | symbol, MethodGuard>]
- * @typedef {import('@endo/patterns').InterfaceGuard<T>} InterfaceGuard
- */
-/** @typedef {import('@agoric/zone').Zone} Zone */
-
+// TODO Type InterfaceGuard better than InterfaceGuard<any>
 /**
  * @template {AssetKind} K
- * @param {Zone} issuerZone
+ * @param {import('@agoric/zone').Zone} issuerZone
  * @param {string} name
  * @param {Brand<K>} brand
- * @param {InterfaceGuard} PaymentI
+ * @param {import('@endo/patterns').InterfaceGuard<any>} PaymentI
  * @returns {() => Payment<K>}
  */
 export const preparePaymentKind = (issuerZone, name, brand, PaymentI) => {
diff --git a/packages/ERTP/src/paymentLedger.js b/packages/ERTP/src/paymentLedger.js
index 4bb674124cf4..bfa57b74f53d 100644
--- a/packages/ERTP/src/paymentLedger.js
+++ b/packages/ERTP/src/paymentLedger.js
@@ -10,8 +10,6 @@ import { preparePurseKind } from './purse.js';
 import '@agoric/store/exported.js';
 import { BrandI, makeIssuerInterfaces } from './typeGuards.js';
 
-/** @typedef {import('@agoric/zone').Zone} Zone */
-
 const { details: X, quote: q, Fail } = assert;
 
 /**
@@ -69,7 +67,7 @@ const amountShapeFromElementShape = (brand, assetKind, elementShape) => {
  * minting and transfer authority originates here.
  *
  * @template {AssetKind} K
- * @param {Zone} issuerZone
+ * @param {import('@agoric/zone').Zone} issuerZone
  * @param {string} name
  * @param {K} assetKind
  * @param {DisplayInfo<K>} displayInfo
diff --git a/packages/ERTP/src/purse.js b/packages/ERTP/src/purse.js
index acc7080acc97..e8cafa50fa56 100644
--- a/packages/ERTP/src/purse.js
+++ b/packages/ERTP/src/purse.js
@@ -3,20 +3,17 @@ import { AmountMath } from './amountMath.js';
 import { makeTransientNotifierKit } from './transientNotifier.js';
 import { makeAmountStore } from './amountStore.js';
 
-// TODO `InterfaceGuard` type parameter
-/** @typedef {import('@endo/patterns').InterfaceGuard} InterfaceGuard */
-/** @typedef {import('@agoric/zone').Zone} Zone */
-
 const { Fail } = assert;
 
+// TODO Type InterfaceGuard better than InterfaceGuard<any>
 /**
- * @param {Zone} issuerZone
+ * @param {import('@agoric/zone').Zone} issuerZone
  * @param {string} name
  * @param {AssetKind} assetKind
  * @param {Brand} brand
  * @param {{
- *   purse: InterfaceGuard;
- *   depositFacet: InterfaceGuard;
+ *   purse: import('@endo/patterns').InterfaceGuard<any>;
+ *   depositFacet: import('@endo/patterns').InterfaceGuard<any>;
  * }} PurseIKit
  * @param {{
  *   depositInternal: any;
diff --git a/packages/ERTP/src/types-ambient.js b/packages/ERTP/src/types-ambient.js
index 0bdc50acee09..59c4388b7d06 100644
--- a/packages/ERTP/src/types-ambient.js
+++ b/packages/ERTP/src/types-ambient.js
@@ -2,11 +2,6 @@
 
 /// <reference types="ses"/>
 
-/**
- * @template {Key} [K=Key]
- * @typedef {import('@endo/patterns').CopyBag<K>} CopyBag
- */
-
 /**
  * @template {AssetKind} [K=AssetKind]
  * @typedef {object} Amount Amounts are descriptions of digital assets,
@@ -22,8 +17,8 @@
  */
 
 /**
- * @typedef {NatValue | SetValue | CopySet | CopyBag} AmountValue An
- *   `AmountValue` describes a set or quantity of assets that can be owned or
+ * @typedef {NatValue | SetValue | CopySet | import('@endo/patterns').CopyBag} AmountValue
+ *   An `AmountValue` describes a set or quantity of assets that can be owned or
  *   shared.
  *
  *   A fungible `AmountValue` uses a non-negative bigint to represent a quantity
@@ -58,7 +53,7 @@
  *   : K extends 'copySet'
  *   ? CopySet
  *   : K extends 'copyBag'
- *   ? CopyBag
+ *   ? import('@endo/patterns').CopyBag
  *   : never} AssetValueForKind
  */
 
@@ -70,7 +65,7 @@
  *   ? 'set'
  *   : V extends CopySet
  *   ? 'copySet'
- *   : V extends CopyBag
+ *   : V extends import('@endo/patterns').CopyBag
  *   ? 'copyBag'
  *   : never} AssetKindForValue
  */
diff --git a/packages/ERTP/test/unitTests/mathHelpers/test-copyBagMathHelpers.js b/packages/ERTP/test/unitTests/mathHelpers/test-copyBagMathHelpers.js
index 64e0ed9bd858..b3e7e6df9cfe 100644
--- a/packages/ERTP/test/unitTests/mathHelpers/test-copyBagMathHelpers.js
+++ b/packages/ERTP/test/unitTests/mathHelpers/test-copyBagMathHelpers.js
@@ -65,7 +65,7 @@ test('copyBag with strings getValue', t => {
   );
   t.deepEqual(
     getCopyBagEntries(
-      /** @type {CopyBag} */ (
+      /** @type {import('@endo/patterns').CopyBag} */ (
         m.getValue(
           mockBrand,
           harden({ brand: mockBrand, value: makeBag(['1']) }),