diff --git a/media/java/android/media/MediaPlayer.java b/media/java/android/media/MediaPlayer.java
index 85a32caba65aa..f74516366b096 100644
--- a/media/java/android/media/MediaPlayer.java
+++ b/media/java/android/media/MediaPlayer.java
@@ -1181,7 +1181,8 @@ public class MediaPlayer
     /**
      * Gets the duration of the file.
      *
-     * @return the duration in milliseconds
+     * @return the duration in milliseconds, if no duration is available
+     *         (for example, if streaming live content), -1 is returned.
      */
     public native int getDuration();