diff --git a/includes/common.inc b/includes/common.inc
index 9a28c06..56e493b 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -1558,6 +1558,10 @@ function url($path = NULL, $options = array()) {
   }
   elseif (!empty($path) && !$options['alias']) {
     $path = drupal_get_path_alias($path, isset($options['language']) ? $options['language']->language : '');
+    // Strip leading slashes from internal paths to prevent them becoming external
+    // URLs without protocol. /example.com should not be turned into
+    // //example.com.
+    $path = ltrim($path, '/');
   }
 
   if (function_exists('custom_url_rewrite_outbound')) {