diff --git a/packages/zoe/src/typeGuards.js b/packages/zoe/src/typeGuards.js
index 0c1d7a02ddb..d1324aee24f 100644
--- a/packages/zoe/src/typeGuards.js
+++ b/packages/zoe/src/typeGuards.js
@@ -367,7 +367,7 @@ export const ZoeServiceI = M.interface('ZoeService', {
   }),
   getInvitationDetails: M.call(M.eref(InvitationShape)).returns(M.any()),
   getProposalShapeForInvitation: M.call(InvitationHandleShape).returns(
-    M.opt(ProposalShape),
+    M.opt(M.pattern()),
   ),
 });
 
diff --git a/packages/zoe/test/unitTests/zcf/offer-proposalShape.test.js b/packages/zoe/test/unitTests/zcf/offer-proposalShape.test.js
new file mode 100644
index 00000000000..ed4ea98cd4a
--- /dev/null
+++ b/packages/zoe/test/unitTests/zcf/offer-proposalShape.test.js
@@ -0,0 +1,143 @@
+import { test } from '@agoric/swingset-vat/tools/prepare-test-env-ava.js';
+
+import path from 'path';
+
+import { E } from '@endo/eventual-send';
+import bundleSource from '@endo/bundle-source';
+
+import { M } from '@endo/patterns';
+import { AmountShape } from '@agoric/ertp';
+import { makeZoeForTest } from '../../../tools/setup-zoe.js';
+import { setup } from '../setupBasicMints.js';
+import { makeFakeVatAdmin } from '../../../tools/fakeVatAdmin.js';
+
+const dirname = path.dirname(new URL(import.meta.url).pathname);
+
+const contractRoot = `${dirname}/zcfTesterContract.js`;
+
+test(`ProposalShapes mismatch`, async t => {
+  const { moolaIssuer, simoleanIssuer, moola, moolaMint } = setup();
+  let testJig;
+  const setJig = jig => {
+    testJig = jig;
+  };
+  const { admin: fakeVatAdminSvc, vatAdminState } = makeFakeVatAdmin(setJig);
+  /** @type {ZoeService} */
+  const zoe = makeZoeForTest(fakeVatAdminSvc);
+
+  // pack the contract
+  const bundle = await bundleSource(contractRoot);
+  // install the contract
+  vatAdminState.installBundle('b1-zcftester', bundle);
+  const installation = await E(zoe).installBundleID('b1-zcftester');
+
+  // Alice creates an instance
+  const issuerKeywordRecord = harden({
+    Pixels: moolaIssuer,
+    Money: simoleanIssuer,
+  });
+
+  await E(zoe).startInstance(installation, issuerKeywordRecord);
+
+  // The contract uses the testJig so the contractFacet
+  // is available here for testing purposes
+  /** @type {ZCF} */
+  // @ts-expect-error cast
+  const zcf = testJig.zcf;
+
+  const boring = () => {
+    return 'ok';
+  };
+
+  const proposalShape = M.splitRecord({
+    give: { B: AmountShape },
+    exit: { deadline: M.any() },
+  });
+  const invitation = await zcf.makeInvitation(
+    boring,
+    'seat1',
+    {},
+    proposalShape,
+  );
+  const { handle } = await E(zoe).getInvitationDetails(invitation);
+  const shape = await E(zoe).getProposalShapeForInvitation(handle);
+  t.deepEqual(shape, proposalShape);
+
+  const proposal = harden({
+    give: { B: moola(5n) },
+    exit: { onDemand: null },
+  });
+
+  const fiveMoola = moolaMint.mintPayment(moola(5n));
+  await t.throwsAsync(
+    () =>
+      E(zoe).offer(invitation, proposal, {
+        B: fiveMoola,
+      }),
+    {
+      message:
+        '"seat1" proposal: exit: {"onDemand":null} - Must have missing properties ["deadline"]',
+    },
+  );
+  t.falsy(vatAdminState.getHasExited());
+  // The moola was not deposited.
+  t.true(await E(moolaIssuer).isLive(fiveMoola));
+});
+
+test(`ProposalShapes matched`, async t => {
+  const { moolaIssuer, simoleanIssuer } = setup();
+  let testJig;
+  const setJig = jig => {
+    testJig = jig;
+  };
+  const { admin: fakeVatAdminSvc, vatAdminState } = makeFakeVatAdmin(setJig);
+  /** @type {ZoeService} */
+  const zoe = makeZoeForTest(fakeVatAdminSvc);
+
+  // pack the contract
+  const bundle = await bundleSource(contractRoot);
+  // install the contract
+  vatAdminState.installBundle('b1-zcftester', bundle);
+  const installation = await E(zoe).installBundleID('b1-zcftester');
+
+  // Alice creates an instance
+  const issuerKeywordRecord = harden({
+    Pixels: moolaIssuer,
+    Money: simoleanIssuer,
+  });
+
+  await E(zoe).startInstance(installation, issuerKeywordRecord);
+
+  // The contract uses the testJig so the contractFacet
+  // is available here for testing purposes
+  /** @type {ZCF} */
+  // @ts-expect-error cast
+  const zcf = testJig.zcf;
+
+  const boring = () => {
+    return 'ok';
+  };
+
+  const proposalShape = M.splitRecord({ exit: { onDemand: null } });
+  const invitation = await zcf.makeInvitation(
+    boring,
+    'seat',
+    {},
+    proposalShape,
+  );
+  const { handle } = await E(zoe).getInvitationDetails(invitation);
+  const shape = await E(zoe).getProposalShapeForInvitation(handle);
+  t.deepEqual(shape, proposalShape);
+
+  // onDemand is the default
+  const seat = await E(zoe).offer(invitation);
+
+  const result = await E(seat).getOfferResult();
+  t.is(result, 'ok', `userSeat1 offer result`);
+
+  t.falsy(await E(seat).hasExited());
+  await E(seat).tryExit();
+  t.true(await E(seat).hasExited());
+  const payouts = await E(seat).getPayouts();
+  t.deepEqual(payouts, {});
+});