diff --git a/variablespeed/jni/variablespeed.h b/variablespeed/jni/variablespeed.h
index 07cba0f..cf856da 100644
--- a/variablespeed/jni/variablespeed.h
+++ b/variablespeed/jni/variablespeed.h
@@ -86,7 +86,7 @@
   bool HasSampleRateAndChannels();
   SLuint32 GetSLSampleRate();
   SLuint32 GetSLChannels();
-  size_t GetChannelCount();
+  SLuint32 GetChannelCount();
 
   // The single global audio engine instance.
   static AudioEngine* audioEngine_;