diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 8aa6aabcca2..541132726f4 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -42,6 +42,10 @@
         get notified after MediaCodec is initialized, or they can inject a
         custom `MediaCodecAdapter.Factory` if they want to control how the
         `MediaCodec` is configured.
+    *   Promote `AdaptiveTrackSelection.AdaptationCheckpoint` to `public`
+        visibility in order to allow Kotlin subclasses of
+        `AdaptiveTrackSelection.Factory`
+        ([#8830](https://github.com/google/ExoPlayer/issues/8830)).
 *   UI:
     *   Add builder for `PlayerNotificationManager`.
     *   Add group setting to `PlayerNotificationManager`.
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/trackselection/AdaptiveTrackSelection.java b/library/core/src/main/java/com/google/android/exoplayer2/trackselection/AdaptiveTrackSelection.java
index cef8f7fa64b..6dc3b2f6368 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/trackselection/AdaptiveTrackSelection.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/trackselection/AdaptiveTrackSelection.java
@@ -697,7 +697,7 @@ private static void addCheckpoint(
   }
 
   /** Checkpoint to determine allocated bandwidth. */
-  protected static final class AdaptationCheckpoint {
+  public static final class AdaptationCheckpoint {
 
     /** Total bandwidth in bits per second at which this checkpoint applies. */
     public final long totalBandwidth;