diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 26a0bb2..9df131a 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -319,6 +319,8 @@
                                       audio_io_handle_t *handle);
     static status_t stopAudioSource(audio_io_handle_t handle);
 
+    static status_t setMasterMono(bool mono);
+    static status_t getMasterMono(bool *mono);
 
     // ----------------------------------------------------------------------------