diff --git a/src/pipecat/services/stt_service.py b/src/pipecat/services/stt_service.py
index a16aa0eaa..c442c41eb 100644
--- a/src/pipecat/services/stt_service.py
+++ b/src/pipecat/services/stt_service.py
@@ -120,6 +120,15 @@ class STTService(AIService):
             or STTSettings(),
             **kwargs,
         )
+
+        # Convert Language enum to service-specific format at init time.
+        # Runtime updates are handled by _update_settings(), but init-time
+        # settings bypass that path and need explicit conversion.
+        if isinstance(self._settings.language, Language):
+            converted = self.language_to_service_language(self._settings.language)
+            if converted is not None:
+                self._settings.language = converted
+
         self._audio_passthrough = audio_passthrough
         self._init_sample_rate = sample_rate
         self._sample_rate = 0
diff --git a/src/pipecat/services/tts_service.py b/src/pipecat/services/tts_service.py
index 44fb98826..e2a9190ab 100644
--- a/src/pipecat/services/tts_service.py
+++ b/src/pipecat/services/tts_service.py
@@ -245,6 +245,14 @@ class TTSService(AIService):
             **kwargs,
         )
 
+        # Convert Language enum to service-specific format at init time.
+        # Runtime updates are handled by _update_settings(), but init-time
+        # settings bypass that path and need explicit conversion.
+        if isinstance(self._settings.language, Language):
+            converted = self.language_to_service_language(self._settings.language)
+            if converted is not None:
+                self._settings.language = converted
+
         # Resolve text_aggregation_mode from the new param or deprecated aggregate_sentences
         if aggregate_sentences is not None:
             import warnings