diff --git a/rtcllm/vad.py b/rtcllm/vad.py
index 57b26d9..b5e3b79 100644
--- a/rtcllm/vad.py
+++ b/rtcllm/vad.py
@@ -139,7 +139,8 @@ class AudioTrackVad(MediaStreamTrack):
 		return fs
 
 	def frames_write_wave(self, frames):
-		ndarr = np.frombuffer(b''.join(frames), dtype=np.int16)
+		fb = [ self.frame2btyes(f) for f in frames ]
+		ndarr = np.frombuffer(b''.join(fb), dtype=np.int16)
 		fn = temp_file(suffix='.wav')
 		write(fn, frames[0].sample_rate, ndarr)
 		return fn