diff --git a/extensions/codex/src/app-server/run-attempt.test.ts b/extensions/codex/src/app-server/run-attempt.test.ts
index 488538c8e7e..cc9e6da2fdc 100644
--- a/extensions/codex/src/app-server/run-attempt.test.ts
+++ b/extensions/codex/src/app-server/run-attempt.test.ts
@@ -79,7 +79,7 @@ function useLightweightCodexRuntimePlan(params: EmbeddedRunAttemptParams): void
       resolvedRef: `${params.provider}/${params.modelId}`,
       harnessId: "codex",
     },
-  } as NonNullable<EmbeddedRunAttemptParams["runtimePlan"]>;
+  } as unknown as NonNullable<EmbeddedRunAttemptParams["runtimePlan"]>;
 }
 
 function threadStartResult(threadId = "thread-1") {