diff --git a/laravel/url.php b/laravel/url.php
index b8fb1f46..1e006a94 100644
--- a/laravel/url.php
+++ b/laravel/url.php
@@ -355,6 +355,8 @@ public static function transpose($uri, $parameters)
 	 */
 	public static function valid($url)
 	{
+		if (starts_with($url, '//')) return true;
+
 		return filter_var($url, FILTER_VALIDATE_URL) !== false;
 	}