diff --git a/services/audioflinger/FastMixerState.h b/services/audioflinger/FastMixerState.h
index be1a376..cb54ff1 100644
--- a/services/audioflinger/FastMixerState.h
+++ b/services/audioflinger/FastMixerState.h
@@ -45,6 +45,7 @@
     ExtendedAudioBufferProvider* mBufferProvider; // must be NULL if inactive, or non-NULL if active
     VolumeProvider*         mVolumeProvider; // optional; if NULL then full-scale
     audio_channel_mask_t    mChannelMask;    // AUDIO_CHANNEL_OUT_MONO or AUDIO_CHANNEL_OUT_STEREO
+    audio_format_t          mFormat;         // track format
     int                     mGeneration;     // increment when any field is assigned
 };