diff --git a/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/DefaultMediaItemConverter.java b/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/DefaultMediaItemConverter.java
index 705f2c2508..c72a1fb316 100644
--- a/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/DefaultMediaItemConverter.java
+++ b/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/DefaultMediaItemConverter.java
@@ -45,7 +45,9 @@ public final class DefaultMediaItemConverter implements MediaItemConverter {
   @Override
   public MediaItem toMediaItem(MediaQueueItem item) {
     // `item` came from `toMediaQueueItem()` so the custom JSON data must be set.
-    return getMediaItem(Assertions.checkNotNull(item.getMedia().getCustomData()));
+    MediaInfo mediaInfo = item.getMedia();
+    Assertions.checkNotNull(mediaInfo);
+    return getMediaItem(Assertions.checkNotNull(mediaInfo.getCustomData()));
   }
 
   @Override