diff --git a/tests/entrypoints/openai_api/test_serving_speech.py b/tests/entrypoints/openai_api/test_serving_speech.py
index daf1c5d5b..6508bea6b 100644
--- a/tests/entrypoints/openai_api/test_serving_speech.py
+++ b/tests/entrypoints/openai_api/test_serving_speech.py
@@ -5150,6 +5150,7 @@ class TestTTSAsyncOffloading:
             models=mock_models,
             request_logger=mocker.MagicMock(),
         )
+        server.uploaded_speakers = {}
         yield server
         server.shutdown()
 
diff --git a/vllm_omni/entrypoints/openai/tts_adapters/voxtral.py b/vllm_omni/entrypoints/openai/tts_adapters/voxtral.py
index 4cdf990f2..45e41c79c 100644
--- a/vllm_omni/entrypoints/openai/tts_adapters/voxtral.py
+++ b/vllm_omni/entrypoints/openai/tts_adapters/voxtral.py
@@ -82,7 +82,8 @@ class VoxtralTTSAdapter(ARTTSAdapter):
 
         if request.voice is not None:
             request.voice = request.voice.lower()
-            available_speakers = server._get_available_speakers()
+            available_speakers = set(self.capabilities.supported_speakers)
+            available_speakers.update(self.capabilities.precomputed_speakers)
             if available_speakers and request.voice not in available_speakers:
                 return f"Invalid speaker '{request.voice}'. Supported: {', '.join(sorted(available_speakers))}"