diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index e448756339d..a645a177135 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -35,8 +35,11 @@
     negligible increase in application size, compared to approximately 8MB when
     embedding the library.
 *   OkHttp extension: Upgrade OkHttp dependency to 3.12.11.
-*   MediaSession extension: Set session playback state to `BUFFERING` only when
-    actually playing ([#7206](https://github.com/google/ExoPlayer/issues/7206)).
+*   MediaSession extension:
+    *   One set the playback state to `BUFFERING` if `playWhenReady` is true
+        ([#7206](https://github.com/google/ExoPlayer/issues/7206)).
+    *   Add missing `@Nullable` annotations to `MediaSessionConnector`
+        ([#7234](https://github.com/google/ExoPlayer/issues/7234)).
 *   AV1 extension: Add a heuristic to determine the default number of threads
     used for AV1 playback using the extension.
 
diff --git a/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java b/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java
index 0847686d215..646351aefee 100644
--- a/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java
+++ b/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java
@@ -218,25 +218,25 @@ public interface PlaybackPreparer extends CommandReceiver {
      *
      * @param mediaId The media id of the media item to be prepared.
      * @param playWhenReady Whether playback should be started after preparation.
-     * @param extras A {@link Bundle} of extras passed by the media controller.
+     * @param extras A {@link Bundle} of extras passed by the media controller, may be null.
      */
-    void onPrepareFromMediaId(String mediaId, boolean playWhenReady, Bundle extras);
+    void onPrepareFromMediaId(String mediaId, boolean playWhenReady, @Nullable Bundle extras);
     /**
      * See {@link MediaSessionCompat.Callback#onPrepareFromSearch(String, Bundle)}.
      *
      * @param query The search query.
      * @param playWhenReady Whether playback should be started after preparation.
-     * @param extras A {@link Bundle} of extras passed by the media controller.
+     * @param extras A {@link Bundle} of extras passed by the media controller, may be null.
      */
-    void onPrepareFromSearch(String query, boolean playWhenReady, Bundle extras);
+    void onPrepareFromSearch(String query, boolean playWhenReady, @Nullable Bundle extras);
     /**
      * See {@link MediaSessionCompat.Callback#onPrepareFromUri(Uri, Bundle)}.
      *
      * @param uri The {@link Uri} of the media item to be prepared.
      * @param playWhenReady Whether playback should be started after preparation.
-     * @param extras A {@link Bundle} of extras passed by the media controller.
+     * @param extras A {@link Bundle} of extras passed by the media controller, may be null.
      */
-    void onPrepareFromUri(Uri uri, boolean playWhenReady, Bundle extras);
+    void onPrepareFromUri(Uri uri, boolean playWhenReady, @Nullable Bundle extras);
   }
 
   /**
@@ -336,7 +336,7 @@ public interface RatingCallback extends CommandReceiver {
     void onSetRating(Player player, RatingCompat rating);
 
     /** See {@link MediaSessionCompat.Callback#onSetRating(RatingCompat, Bundle)}. */
-    void onSetRating(Player player, RatingCompat rating, Bundle extras);
+    void onSetRating(Player player, RatingCompat rating, @Nullable Bundle extras);
   }
 
   /** Handles requests for enabling or disabling captions. */
@@ -381,7 +381,7 @@ public interface CustomActionProvider {
      * @param controlDispatcher A {@link ControlDispatcher} that should be used for dispatching
      *     changes to the player.
      * @param action The name of the action which was sent by a media controller.
-     * @param extras Optional extras sent by a media controller.
+     * @param extras Optional extras sent by a media controller, may be null.
      */
     void onCustomAction(
         Player player, ControlDispatcher controlDispatcher, String action, @Nullable Bundle extras);
@@ -1321,42 +1321,42 @@ public void onPrepare() {
     }
 
     @Override
-    public void onPrepareFromMediaId(String mediaId, Bundle extras) {
+    public void onPrepareFromMediaId(String mediaId, @Nullable Bundle extras) {
       if (canDispatchToPlaybackPreparer(PlaybackStateCompat.ACTION_PREPARE_FROM_MEDIA_ID)) {
         playbackPreparer.onPrepareFromMediaId(mediaId, /* playWhenReady= */ false, extras);
       }
     }
 
     @Override
-    public void onPrepareFromSearch(String query, Bundle extras) {
+    public void onPrepareFromSearch(String query, @Nullable Bundle extras) {
       if (canDispatchToPlaybackPreparer(PlaybackStateCompat.ACTION_PREPARE_FROM_SEARCH)) {
         playbackPreparer.onPrepareFromSearch(query, /* playWhenReady= */ false, extras);
       }
     }
 
     @Override
-    public void onPrepareFromUri(Uri uri, Bundle extras) {
+    public void onPrepareFromUri(Uri uri, @Nullable Bundle extras) {
       if (canDispatchToPlaybackPreparer(PlaybackStateCompat.ACTION_PREPARE_FROM_URI)) {
         playbackPreparer.onPrepareFromUri(uri, /* playWhenReady= */ false, extras);
       }
     }
 
     @Override
-    public void onPlayFromMediaId(String mediaId, Bundle extras) {
+    public void onPlayFromMediaId(String mediaId, @Nullable Bundle extras) {
       if (canDispatchToPlaybackPreparer(PlaybackStateCompat.ACTION_PLAY_FROM_MEDIA_ID)) {
         playbackPreparer.onPrepareFromMediaId(mediaId, /* playWhenReady= */ true, extras);
       }
     }
 
     @Override
-    public void onPlayFromSearch(String query, Bundle extras) {
+    public void onPlayFromSearch(String query, @Nullable Bundle extras) {
       if (canDispatchToPlaybackPreparer(PlaybackStateCompat.ACTION_PLAY_FROM_SEARCH)) {
         playbackPreparer.onPrepareFromSearch(query, /* playWhenReady= */ true, extras);
       }
     }
 
     @Override
-    public void onPlayFromUri(Uri uri, Bundle extras) {
+    public void onPlayFromUri(Uri uri, @Nullable Bundle extras) {
       if (canDispatchToPlaybackPreparer(PlaybackStateCompat.ACTION_PLAY_FROM_URI)) {
         playbackPreparer.onPrepareFromUri(uri, /* playWhenReady= */ true, extras);
       }
@@ -1370,7 +1370,7 @@ public void onSetRating(RatingCompat rating) {
     }
 
     @Override
-    public void onSetRating(RatingCompat rating, Bundle extras) {
+    public void onSetRating(RatingCompat rating, @Nullable Bundle extras) {
       if (canDispatchSetRating()) {
         ratingCallback.onSetRating(player, rating, extras);
       }