diff --git a/wp-includes/nav-menu.php b/wp-includes/nav-menu.php
index 503490b67a..6a290bdaa9 100644
--- a/wp-includes/nav-menu.php
+++ b/wp-includes/nav-menu.php
@@ -1124,8 +1124,8 @@ function wp_map_nav_menu_locations( $new_nav_menu_locations, $old_nav_menu_locat
 	 * from within the same group, make an educated guess and map it.
 	 */
 	$common_slug_groups = array(
-		array( 'header', 'main', 'navigation', 'primary', 'top' ),
-		array( 'bottom', 'footer', 'secondary', 'subsidiary' ),
+		array( 'primary', 'menu-1', 'main', 'header', 'navigation', 'top' ),
+		array( 'secondary', 'menu-2', 'footer', 'subsidiary', 'bottom' ),
 		array( 'social' ),
 	);
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 5cd900abbb..739cfb3b46 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-beta4-42025';
+$wp_version = '4.9-beta4-42026';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.