diff --git a/a3p-integration/proposals/s:stake-bld/package.json b/a3p-integration/proposals/s:stake-bld/package.json
index 477b95ba07a..7351caacb7c 100644
--- a/a3p-integration/proposals/s:stake-bld/package.json
+++ b/a3p-integration/proposals/s:stake-bld/package.json
@@ -23,5 +23,8 @@
   "ava": {
     "concurrency": 1
   },
-  "packageManager": "yarn@4.5.1"
+  "packageManager": "yarn@4.5.1",
+  "devDependencies": {
+    "@types/node": "^22.0.0"
+  }
 }
diff --git a/a3p-integration/proposals/s:stake-bld/stakeBld.test.js b/a3p-integration/proposals/s:stake-bld/stakeBld.test.js
index 9333fb302eb..549e4562545 100644
--- a/a3p-integration/proposals/s:stake-bld/stakeBld.test.js
+++ b/a3p-integration/proposals/s:stake-bld/stakeBld.test.js
@@ -30,6 +30,9 @@ test('basic', async t => {
 
   t.is((await currentDelegation()).length, 1, 'just the initial delegation');
 
+  /** @type {import('@agoric/ertp').Brand} */
+  const BLDBrand = brand.BLD;
+
   await walletUtils.broadcastBridgeAction(GOV1ADDR, {
     method: 'executeOffer',
     offer: {
@@ -41,7 +44,7 @@ test('basic', async t => {
       },
       proposal: {
         give: {
-          In: { brand: brand.BLD, value: 10n },
+          In: { brand: BLDBrand, value: 10n },
         },
       },
     },
@@ -55,11 +58,11 @@ test('basic', async t => {
         source: 'continuing',
         previousOffer: 'request-stake',
         invitationMakerName: 'Delegate',
-        invitationArgs: [VALIDATOR_ADDRESS, { brand: brand.BLD, value: 10n }],
+        invitationArgs: [VALIDATOR_ADDRESS, { brand: BLDBrand, value: 10n }],
       },
       proposal: {
         give: {
-          In: { brand: brand.BLD, value: 10n },
+          In: { brand: BLDBrand, value: 10n },
         },
       },
     },
diff --git a/a3p-integration/proposals/s:stake-bld/test-lib/rpc.js b/a3p-integration/proposals/s:stake-bld/test-lib/rpc.js
index 1d62aedf1be..a3ac266ee88 100644
--- a/a3p-integration/proposals/s:stake-bld/test-lib/rpc.js
+++ b/a3p-integration/proposals/s:stake-bld/test-lib/rpc.js
@@ -1,7 +1,7 @@
 /** @file copied from packages/agoric-cli */
 // TODO DRY in https://github.com/Agoric/agoric-sdk/issues/9109
 // @ts-check
-/* global Buffer */
+/* eslint-env node */
 
 import { Fail } from '@endo/errors';
 import {
diff --git a/a3p-integration/proposals/s:stake-bld/test-lib/wallet.js b/a3p-integration/proposals/s:stake-bld/test-lib/wallet.js
index 53d9634e278..e9461522e1d 100644
--- a/a3p-integration/proposals/s:stake-bld/test-lib/wallet.js
+++ b/a3p-integration/proposals/s:stake-bld/test-lib/wallet.js
@@ -29,6 +29,7 @@ import { makeVstorageKit } from './rpc.js';
  */
 export const sendAction = async (bridgeAction, opts) => {
   const { marshaller } = opts;
+  // @ts-expect-error BridgeAction has methods disallowed by Passable
   const offerBody = JSON.stringify(marshaller.toCapData(harden(bridgeAction)));
 
   // tryExit should not require --allow-spend
diff --git a/a3p-integration/proposals/s:stake-bld/tsconfig.json b/a3p-integration/proposals/s:stake-bld/tsconfig.json
new file mode 100644
index 00000000000..8672f62769d
--- /dev/null
+++ b/a3p-integration/proposals/s:stake-bld/tsconfig.json
@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "noEmit": true,
+    "target": "esnext",
+    "module": "esnext",
+    "moduleResolution": "bundler",
+    "allowJs": true,
+    "checkJs": true,
+    "strict": false,
+    "strictNullChecks": true,
+    "noImplicitThis": true,
+    // XXX synthetic-chain has some errors
+    "skipLibCheck": true
+  },
+  "exclude": ["submission"]
+}
diff --git a/a3p-integration/proposals/s:stake-bld/yarn.lock b/a3p-integration/proposals/s:stake-bld/yarn.lock
index 513c7872fe3..1d13185abe2 100644
--- a/a3p-integration/proposals/s:stake-bld/yarn.lock
+++ b/a3p-integration/proposals/s:stake-bld/yarn.lock
@@ -1574,6 +1574,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/node@npm:^22.0.0":
+  version: 22.9.1
+  resolution: "@types/node@npm:22.9.1"
+  dependencies:
+    undici-types: "npm:~6.19.8"
+  checksum: 10c0/ea489ae603aa8874e4e88980aab6f2dad09c755da779c88dd142983bfe9609803c89415ca7781f723072934066f63daf2b3339ef084a8ad1a8079cf3958be243
+  languageName: node
+  linkType: hard
+
 "@types/resolve@npm:1.17.1":
   version: 1.17.1
   resolution: "@types/resolve@npm:1.17.1"
@@ -4689,6 +4698,7 @@ __metadata:
     "@endo/errors": "npm:^1.2.2"
     "@endo/far": "npm:^1.0.4"
     "@endo/init": "npm:^1.0.4"
+    "@types/node": "npm:^22.0.0"
     agoric: "npm:0.21.2-dev-5676146.0"
     ava: "npm:^5.3.1"
     execa: "npm:^8.0.1"
@@ -5290,6 +5300,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"undici-types@npm:~6.19.8":
+  version: 6.19.8
+  resolution: "undici-types@npm:6.19.8"
+  checksum: 10c0/078afa5990fba110f6824823ace86073b4638f1d5112ee26e790155f481f2a868cc3e0615505b6f4282bdf74a3d8caad715fd809e870c2bb0704e3ea6082f344
+  languageName: node
+  linkType: hard
+
 "unicorn-magic@npm:^0.3.0":
   version: 0.3.0
   resolution: "unicorn-magic@npm:0.3.0"