diff --git a/static/js/chat.js b/static/js/chat.js
index 1aae61fcf..62763cabd 100644
--- a/static/js/chat.js
+++ b/static/js/chat.js
@@ -6149,9 +6149,12 @@ import { invalidateSettings } from './appConfig.js';
         cache: 'no-store',
       });
       if (!_getForegroundStreamState() || _backgroundStreams.has(sid)) return;
+      // The server now reports "no active stream" as 200 {status:"idle"} (an
+      // older server used 404); a body with status "streaming" means it is NOT
+      // stale. Accept both so the watchdog keeps working across deploys.
       if (res.status !== 404 && !res.ok) return;
       let _probe = null;
-      try { _probe = await res.json(); } catch (_) { /* An invalid response is not an idle stream. */ }
+      try { _probe = await res.json(); } catch (_) { _probe = null; }
       const _noActiveStream = res.status === 404 || (res.ok && _probe &&
         typeof _probe.status === 'string' && _probe.status !== 'streaming');
       if (!_noActiveStream) return;