diff --git a/src/lib/__tests__/geminiLive.test.ts b/src/lib/__tests__/geminiLive.test.ts
index eb1f980..0e1b610 100644
--- a/src/lib/__tests__/geminiLive.test.ts
+++ b/src/lib/__tests__/geminiLive.test.ts
@@ -78,9 +78,9 @@ describe("openGeminiLiveSession (raw WS)", () => {
     expect(setup.setup.systemInstruction.parts[0].text).toContain(
       "un bailleur qui propose un appartement",
     );
-    // ⚠ DEBUG : autres champs encore absents — réintégration champ par champ.
-    expect(setup.setup.inputAudioTranscription).toBeUndefined();
-    expect(setup.setup.outputAudioTranscription).toBeUndefined();
+    expect(setup.setup.inputAudioTranscription).toEqual({});
+    expect(setup.setup.outputAudioTranscription).toEqual({});
+    // ⚠ DEBUG : realtimeInputConfig (VAD) encore absent — prochain push.
     expect(setup.setup.realtimeInputConfig).toBeUndefined();
   });
 
diff --git a/src/lib/geminiLive.ts b/src/lib/geminiLive.ts
index 62203e5..352b415 100644
--- a/src/lib/geminiLive.ts
+++ b/src/lib/geminiLive.ts
@@ -224,6 +224,8 @@ function buildSetupFrame(systemPrompt: string): string {
       systemInstruction: {
         parts: [{ text: systemPrompt }],
       },
+      inputAudioTranscription: {},
+      outputAudioTranscription: {},
     },
   });
 }