diff --git a/wp-includes/media.php b/wp-includes/media.php
index 506c86c5ee..e929ad47ea 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -941,10 +941,11 @@ function gallery_shortcode( $attr ) {
 	 *
 	 * @see gallery_shortcode()
 	 *
-	 * @param string $output The gallery output. Default empty.
-	 * @param array  $attr   Attributes of the gallery shortcode.
+	 * @param string $output   The gallery output. Default empty.
+	 * @param array  $attr     Attributes of the gallery shortcode.
+	 * @param int    $instance Unique numeric ID of this gallery shortcode instance.
 	 */
-	$output = apply_filters( 'post_gallery', '', $attr );
+	$output = apply_filters( 'post_gallery', '', $attr, $instance );
 	if ( $output != '' ) {
 		return $output;
 	}
@@ -1214,10 +1215,11 @@ function wp_playlist_shortcode( $attr ) {
 	 *
 	 * @since 3.9.0
 	 *
-	 * @param string $output Playlist output. Default empty.
-	 * @param array  $attr   An array of shortcode attributes.
+	 * @param string $output   Playlist output. Default empty.
+	 * @param array  $attr     An array of shortcode attributes.
+	 * @param int    $instance Unique numeric ID of this playlist shortcode instance.
 	 */
-	$output = apply_filters( 'post_playlist', '', $attr );
+	$output = apply_filters( 'post_playlist', '', $attr, $instance );
 	if ( $output != '' ) {
 		return $output;
 	}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 2a56a5aad0..548c081635 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-alpha-31303';
+$wp_version = '4.2-alpha-31304';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.