diff --git a/contract/src/offer-up-proposal.js b/contract/src/offer-up-proposal.js
index d35e1e3..a65d516 100644
--- a/contract/src/offer-up-proposal.js
+++ b/contract/src/offer-up-proposal.js
@@ -15,6 +15,12 @@ const marshalData = makeMarshal(_val => Fail`data only`);
 const IST_UNIT = 1_000_000n;
 const CENT = IST_UNIT / 100n;
 
+/**
+ * @import {ERef} from '@endo/far';
+ * @import {StorageNode} from '@agoric/internal/src/lib-chainStorage.js';
+ * @import {BootstrapManifest} from '@agoric/vats/src/core/lib-boot.js';
+ */
+
 /**
  * Make a storage node for auxilliary data for a value on the board.
  *
@@ -36,7 +42,11 @@ const publishBrandInfo = async (chainStorage, board, brand) => {
   await E(node).setValue(JSON.stringify(aux));
 };
 
+// TODO get these from agoric-sdk
+/** @typedef {Record<string, any>} BootstrapPowers */
+
 /**
+ *
  * Core eval script to start contract
  *
  * @param {BootstrapPowers} permittedPowers
@@ -47,19 +57,16 @@ export const startOfferUpContract = async permittedPowers => {
     consume: { board, chainStorage, startUpgradable, zoe },
     brand: {
       consume: { IST: istBrandP },
-      // @ts-expect-error dynamic extension to promise space
       produce: { Item: produceItemBrand },
     },
     issuer: {
       consume: { IST: istIssuerP },
-      // @ts-expect-error dynamic extension to promise space
       produce: { Item: produceItemIssuer },
     },
     installation: {
       consume: { offerUp: offerUpInstallationP },
     },
     instance: {
-      // @ts-expect-error dynamic extension to promise space
       produce: { offerUp: produceInstance },
     },
   } = permittedPowers;
@@ -98,7 +105,7 @@ export const startOfferUpContract = async permittedPowers => {
   console.log('offerUp (re)started');
 };
 
-/** @type { import("@agoric/vats/src/core/lib-boot").BootstrapManifest } */
+/** @type {BootstrapManifest} */
 const offerUpManifest = {
   [startOfferUpContract.name]: {
     consume: {