diff --git a/services/audioflinger/FastMixer.h b/services/audioflinger/FastMixer.h
index 1c86d9a..1d332e0 100644
--- a/services/audioflinger/FastMixer.h
+++ b/services/audioflinger/FastMixer.h
@@ -76,6 +76,8 @@
     size_t          mMixerBufferSize;
     audio_format_t  mMixerBufferFormat; // mixer output format: AUDIO_FORMAT_PCM_(16_BIT|FLOAT).
 
+    uint32_t        mAudioChannelCount; // audio channel count, excludes haptic channels.
+
     enum {UNDEFINED, MIXED, ZEROED} mMixerBufferState;
     NBAIO_Format    mFormat;
     unsigned        mSampleRate;