diff --git a/wp-includes/nav-menu.php b/wp-includes/nav-menu.php
index 9b6eeba9b3..863183a92b 100644
--- a/wp-includes/nav-menu.php
+++ b/wp-includes/nav-menu.php
@@ -456,11 +456,15 @@ function wp_update_nav_menu_item( $menu_id = 0, $menu_item_db_id = 0, $menu_item
 
 	$original_parent = 0 < $menu_item_db_id ? get_post_field( 'post_parent', $menu_item_db_id ) : 0;
 
-	if ( 'custom' != $args['menu-item-type'] ) {
-		/* if non-custom menu item, then:
-			* use original object's URL
-			* blank default title to sync with original object's
-		*/
+	if ( 'custom' === $args['menu-item-type'] ) {
+		// If custom menu item, trim the URL.
+		$args[ 'menu-item-url' ] = trim( $args[ 'menu-item-url' ] );
+	} else {
+		/*
+		 * If non-custom menu item, then:
+		 * - use the original object's URL.
+		 * - blank default title to sync with the original object's title.
+		 */
 
 		$args['menu-item-url'] = '';
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index dff026e394..7c55ae5df1 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-45654';
+$wp_version = '5.3-alpha-45655';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.