diff --git a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/upstream/Loader.java b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/upstream/Loader.java
index 46923e540b..71212e7eea 100644
--- a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/upstream/Loader.java
+++ b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/upstream/Loader.java
@@ -326,10 +326,10 @@ public final class Loader implements LoaderErrorThrower {
 
     private static final String TAG = "LoadTask";
 
-    private static final int MSG_START = 0;
-    private static final int MSG_FINISH = 1;
-    private static final int MSG_IO_EXCEPTION = 2;
-    private static final int MSG_FATAL_ERROR = 3;
+    private static final int MSG_START = 1;
+    private static final int MSG_FINISH = 2;
+    private static final int MSG_IO_EXCEPTION = 3;
+    private static final int MSG_FATAL_ERROR = 4;
 
     public final int defaultMinRetryCount;
 
diff --git a/libraries/ui/src/main/java/androidx/media3/ui/PlayerNotificationManager.java b/libraries/ui/src/main/java/androidx/media3/ui/PlayerNotificationManager.java
index 768274cbab..fd65683c4c 100644
--- a/libraries/ui/src/main/java/androidx/media3/ui/PlayerNotificationManager.java
+++ b/libraries/ui/src/main/java/androidx/media3/ui/PlayerNotificationManager.java
@@ -650,8 +650,8 @@ public class PlayerNotificationManager {
 
   // Internal messages.
 
-  private static final int MSG_START_OR_UPDATE_NOTIFICATION = 0;
-  private static final int MSG_UPDATE_NOTIFICATION_BITMAP = 1;
+  private static final int MSG_START_OR_UPDATE_NOTIFICATION = 1;
+  private static final int MSG_UPDATE_NOTIFICATION_BITMAP = 2;
 
   /**
    * Visibility of notification on the lock screen. One of {@link