diff --git a/extensions/codex/src/app-server/run-attempt.test.ts b/extensions/codex/src/app-server/run-attempt.test.ts
index f8afccf4371..087f0b5e043 100644
--- a/extensions/codex/src/app-server/run-attempt.test.ts
+++ b/extensions/codex/src/app-server/run-attempt.test.ts
@@ -1461,9 +1461,10 @@ describe("runCodexAppServerAttempt", () => {
       return undefined;
     });
 
-    await expect(
-      runCodexAppServerAttempt(createParamsWithRuntimePlan(sessionFile, workspaceDir)),
-    ).rejects.toThrow("turn start exploded");
+    const params = createParams(sessionFile, workspaceDir);
+    params.runtimePlan = createCodexRuntimePlanFixture();
+
+    await expect(runCodexAppServerAttempt(params)).rejects.toThrow("turn start exploded");
 
     expect(llmInput).toHaveBeenCalledTimes(1);
     expect(llmOutput).toHaveBeenCalledTimes(1);