diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index dab6d91..1c3cf5d 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -2180,7 +2180,13 @@
 
 void AudioFlinger::PlaybackThread::threadLoop_exit()
 {
-    // Default implementation has nothing to do
+    {
+        Mutex::Autolock _l(mLock);
+        for (size_t i = 0; i < mTracks.size(); i++) {
+            sp<Track> track = mTracks[i];
+            track->invalidate();
+        }
+    }
 }
 
 /*