diff --git a/wp-includes/bookmark-template.php b/wp-includes/bookmark-template.php
index 95a09f0b08..47bfb4a181 100644
--- a/wp-includes/bookmark-template.php
+++ b/wp-includes/bookmark-template.php
@@ -214,6 +214,12 @@ function wp_list_bookmarks( $args = '' ) {
 
 	$output = '';
 
+	if ( ! is_array( $r['class'] ) ) {
+		$r['class'] = explode( ' ', $r['class'] );
+	}
+ 	$r['class'] = array_map( 'sanitize_html_class', $r['class'] );
+ 	$r['class'] = trim( join( ' ', $r['class'] ) );
+
 	if ( $r['categorize'] ) {
 		$cats = get_terms( 'link_category', array(
 			'name__like' => $r['category_name'],
diff --git a/wp-includes/version.php b/wp-includes/version.php
index cc197988a3..a4d6979e5a 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.3-alpha-32905';
+$wp_version = '4.3-alpha-32906';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.