diff --git a/app/src/main/java/ch/blinkenlights/android/vanilla/PlaybackService.java b/app/src/main/java/ch/blinkenlights/android/vanilla/PlaybackService.java
index 2833a19b..b784d109 100644
--- a/app/src/main/java/ch/blinkenlights/android/vanilla/PlaybackService.java
+++ b/app/src/main/java/ch/blinkenlights/android/vanilla/PlaybackService.java
@@ -624,6 +624,10 @@ public final class PlaybackService extends Service
 		// defer wakelock and close audioFX
 		enterSleepState();
 
+		// stop getting preference changes.
+		getSettings(this).unregisterOnSharedPreferenceChangeListener(this);
+
+		// shutdown all observers.
 		MediaLibrary.unregisterLibraryObserver(mObserver);
 		mPlaylistObserver.unregister();