diff --git a/src/cron/cron-protocol-conformance.test.ts b/src/cron/cron-protocol-conformance.test.ts
index 698f5e0038d..35d53f821af 100644
--- a/src/cron/cron-protocol-conformance.test.ts
+++ b/src/cron/cron-protocol-conformance.test.ts
@@ -110,6 +110,9 @@ describe("cron protocol conformance", () => {
       "billing",
       "timeout",
       "model_not_found",
+      "empty_response",
+      "no_error_details",
+      "unclassified",
       "unknown",
     ]);
   });