diff --git a/packages/support/acp-snapshot/tests/harness.spec.ts b/packages/support/acp-snapshot/tests/harness.spec.ts
index 2f54b7781d..4aa24e290a 100644
--- a/packages/support/acp-snapshot/tests/harness.spec.ts
+++ b/packages/support/acp-snapshot/tests/harness.spec.ts
@@ -480,6 +480,7 @@ describe('runScenario', () => {
 
   it.each([
     [{ op: 'prompt', text: 'x' }, /prompt before newSession/],
+    [{ op: 'promptAndWaitForAgentMessage', text: 'x', waitForText: 'later' }, /promptAndWaitForAgentMessage before newSession/],
     [{ op: 'promptExpectError', text: 'x' }, /promptExpectError before newSession/],
     [{ op: 'promptAndCancel', text: 'x' }, /promptAndCancel before newSession/],
     [{ op: 'cancel' }, /cancel before newSession/],