diff --git a/include/media/IAudioFlinger.h b/include/media/IAudioFlinger.h
index 04ac3ee..86e228b 100644
--- a/include/media/IAudioFlinger.h
+++ b/include/media/IAudioFlinger.h
@@ -65,6 +65,7 @@
                                 track_flags_t flags,
                                 const sp<IMemory>& sharedBuffer,
                                 audio_io_handle_t output,
+                                pid_t tid,  // -1 means unused, otherwise must be valid non-0
                                 int *sessionId,
                                 status_t *status) = 0;