diff --git a/src/wp-admin/css/wp-admin.css b/src/wp-admin/css/wp-admin.css
index 6a49129b3a..02118b40f1 100644
--- a/src/wp-admin/css/wp-admin.css
+++ b/src/wp-admin/css/wp-admin.css
@@ -4901,6 +4901,10 @@ p.popular-tags a {
 	border-style: solid;
 }
 
+.wp-customizer .ac_results {
+	z-index: 500000;
+}
+
 .ac_results li {
 	padding: 2px 5px;
 	white-space: nowrap;
diff --git a/src/wp-admin/customize.php b/src/wp-admin/customize.php
index 1728a983b2..b247b19d28 100644
--- a/src/wp-admin/customize.php
+++ b/src/wp-admin/customize.php
@@ -56,7 +56,7 @@ do_action( 'customize_controls_enqueue_scripts' );
 wp_user_settings();
 _wp_admin_html_begin();
 
-$body_class = 'wp-core-ui js';
+$body_class = 'wp-core-ui wp-customizer js';
 
 if ( wp_is_mobile() ) :
 	$body_class .= ' mobile';