diff --git a/src/slack/monitor/message-handler/dispatch.ts b/src/slack/monitor/message-handler/dispatch.ts
index bfd58c80c8e..f03b1bd8d73 100644
--- a/src/slack/monitor/message-handler/dispatch.ts
+++ b/src/slack/monitor/message-handler/dispatch.ts
@@ -553,10 +553,8 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
       }
       // Fall back to normal delivery with the full accumulated streamed text
       // so the user receives the complete answer even when stop() fails.
-      // Bind to a local const so TypeScript narrows away null before spread.
-      const fallbackPayload = lastStreamPayload;
-      if (orphanDeleted && fallbackPayload && streamedText) {
-        await deliverNormally({ ...fallbackPayload, text: streamedText }, finalStream.threadTs);
+      if (orphanDeleted && lastStreamPayload !== null && streamedText) {
+        await deliverNormally({ ...lastStreamPayload, text: streamedText }, finalStream.threadTs);
       }
     }
   }