diff --git a/src/agents/pi-embedded-helpers/errors.ts b/src/agents/pi-embedded-helpers/errors.ts
index 8f52c740aab6..9a5b38d30761 100644
--- a/src/agents/pi-embedded-helpers/errors.ts
+++ b/src/agents/pi-embedded-helpers/errors.ts
@@ -652,10 +652,11 @@ function classifyFailoverClassificationFromHttpStatus(
   }
   if (status === 429) {
     if (
-      messageReason === "billing" &&
-      (isProvider(provider, "moonshot") || isProvider(provider, "kimi"))
+      message &&
+      (isProvider(provider, "moonshot") || isProvider(provider, "kimi")) &&
+      isBillingErrorMessage(message)
     ) {
-      return messageClassification;
+      return toReasonClassification("billing");
     }
     return toReasonClassification("rate_limit");
   }