diff --git a/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/MediaPlayerManager.kt b/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/MediaPlayerManager.kt
index 2a4cbbdc..93588750 100644
--- a/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/MediaPlayerManager.kt
+++ b/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/MediaPlayerManager.kt
@@ -248,7 +248,10 @@ class MediaPlayerManager(
         mediaControllerFuture = MediaController.Builder(
             context,
             sessionToken
-        ).buildAsync()
+        )
+            // Specify mainThread explicitely
+            .setApplicationLooper(Looper.getMainLooper())
+            .buildAsync()
 
         mediaControllerFuture?.addListener({
             controller = mediaControllerFuture?.get()
diff --git a/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/RxBus.kt b/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/RxBus.kt
index 9912cf0d..8524fdff 100644
--- a/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/RxBus.kt
+++ b/ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/RxBus.kt
@@ -12,6 +12,11 @@ import org.moire.ultrasonic.domain.Track
 
 class RxBus {
 
+    /**
+     * IMPORTANT: methods like .delay() or .throttle() will implicitly change the thread to the
+     * RxComputationScheduler. Always use the function call with the additional arguments of the
+     * desired scheduler
+     **/
     companion object {
 
         fun mainThread(): Scheduler = AndroidSchedulers.mainThread()
@@ -52,7 +57,8 @@ class RxBus {
             playerStatePublisher
                 .replay(1)
                 .autoConnect(0)
-                .throttleLatest(300, TimeUnit.MILLISECONDS)
+                // Need to specify thread, see comment at beginning
+                .throttleLatest(300, TimeUnit.MILLISECONDS, mainThread())
 
         val playlistPublisher: PublishSubject<List<Track>> =
             PublishSubject.create()
@@ -64,7 +70,8 @@ class RxBus {
             playlistPublisher
                 .replay(1)
                 .autoConnect(0)
-                .throttleLatest(300, TimeUnit.MILLISECONDS)
+                // Need to specify thread, see comment at beginning
+                .throttleLatest(300, TimeUnit.MILLISECONDS, mainThread())
 
         val trackDownloadStatePublisher: PublishSubject<TrackDownloadState> =
             PublishSubject.create()