diff --git a/include/media/mediaplayer.h b/include/media/mediaplayer.h
index 58906d1..255a67b 100644
--- a/include/media/mediaplayer.h
+++ b/include/media/mediaplayer.h
@@ -173,6 +173,7 @@
     };
 
     sp<IMediaPlayer>            mPlayer;
+    thread_id_t                 mLockThreadId;
     Mutex                       mLock;
     Mutex                       mNotifyLock;
     Condition                   mSignal;