diff --git a/src/lib/translator.js b/src/lib/translator.js
index 684c2df..5ae67b6 100644
--- a/src/lib/translator.js
+++ b/src/lib/translator.js
@@ -735,11 +735,15 @@ User: ${userMessage}`;
         );
       });
     } catch (err) {
+      // Synchronous setup failures (most importantly `!this.isReady` — the Puter
+      // bridge hasn't finished its handshake) must PROPAGATE, not resolve to a
+      // string. The sole caller (sidebar-chat) discards chatStream's return value
+      // and relies on a thrown error to render the error bubble + retry button;
+      // returning a string here left the "thinking…" spinner stranded forever
+      // with no error and no retry. (Promise-path failures — timeout, abort,
+      // success:false — already reject and are unaffected.)
       console.error('[SkillBridge] Chat stream error:', err);
-      return (
-        (typeof CHAT_ERROR_LABELS !== 'undefined' && CHAT_ERROR_LABELS[targetLang]) ||
-        'Sorry, I could not generate a response. Please try again.'
-      );
+      throw err;
     }
   }
 
diff --git a/tests/translator.test.js b/tests/translator.test.js
index 2a92c55..68283cf 100644
--- a/tests/translator.test.js
+++ b/tests/translator.test.js
@@ -287,3 +287,15 @@ describe('Language JSON files', () => {
     });
   });
 });
+
+describe('chatStream — bridge-not-ready propagates as a rejection', () => {
+  test('rejects (does not silently resolve to a string) when the bridge is not ready', async () => {
+    const t = new SkilljarTranslator();
+    t.isReady = false;
+    // The sole caller (sidebar-chat) discards chatStream's return value and
+    // relies on a thrown error to render the error bubble + retry button. If
+    // this resolves to a string instead, the "thinking…" spinner is stranded
+    // forever with no error and no retry.
+    await expect(t.chatStream('hello', 'ko', '', () => {}, {})).rejects.toThrow('Bridge not ready');
+  });
+});