diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 7b76789739..924b69a951 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -128,6 +128,9 @@
 *   HLS Extension:
 *   DASH Extension:
 *   Smooth Streaming Extension:
+    *   Fix a `Bad magic number for Bundle` error when playing SmoothStreaming
+        streams with text tracks
+        ([#1779](https://github.com/androidx/media/issues/1779)).
 *   RTSP Extension:
     *   Fix user info removal for URLs that contain encoded @ characters
         ([#1138](https://github.com/androidx/media/pull/1138)).
diff --git a/libraries/extractor/src/main/java/androidx/media3/extractor/mp4/FragmentedMp4Extractor.java b/libraries/extractor/src/main/java/androidx/media3/extractor/mp4/FragmentedMp4Extractor.java
index 3a556970ba..a3ef9643b3 100644
--- a/libraries/extractor/src/main/java/androidx/media3/extractor/mp4/FragmentedMp4Extractor.java
+++ b/libraries/extractor/src/main/java/androidx/media3/extractor/mp4/FragmentedMp4Extractor.java
@@ -448,7 +448,7 @@ public class FragmentedMp4Extractor implements Extractor {
     if (sideloadedTrack != null) {
       TrackBundle bundle =
           new TrackBundle(
-              output.track(0, sideloadedTrack.type),
+              extractorOutput.track(0, sideloadedTrack.type),
               new TrackSampleTable(
                   sideloadedTrack,
                   /* offsets= */ new long[0],