diff --git a/include/hardware/audio.h b/include/hardware/audio.h
index ed97728..f32a520 100644
--- a/include/hardware/audio.h
+++ b/include/hardware/audio.h
@@ -215,9 +215,9 @@
 /**
  * return the frame size (number of bytes per sample).
  */
-static inline uint32_t audio_stream_frame_size(struct audio_stream *s)
+static inline size_t audio_stream_frame_size(struct audio_stream *s)
 {
-    int chan_samp_sz;
+    size_t chan_samp_sz;
 
     switch (s->get_format(s)) {
     case AUDIO_FORMAT_PCM_16_BIT: