diff --git a/src/assistant/lib/tts/repositories/base.py b/src/assistant/lib/tts/repositories/base.py
index 14f3275..6d1ce15 100644
--- a/src/assistant/lib/tts/repositories/base.py
+++ b/src/assistant/lib/tts/repositories/base.py
@@ -12,7 +12,7 @@ class TTSBaseRepository(abc.ABC):
     @property
     @abc.abstractmethod
     def voice_models(self) -> models.LIST_VOICE_MODELS_TYPE:
-        ...
+        raise NotImplementedError
 
     @abc.abstractmethod
     def get_audio_as_bytes(self, request: models.TTSCreateRequestModel) -> models.TTSCreateResponseModel: