diff --git a/includes/common.inc b/includes/common.inc
index 0f8312aebdd0e90b6aab4f7b7d51f5fa5437d194..e53865ee4e5d82b08f6e0973157bfc40078577d3 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -617,10 +617,10 @@ function valid_email_address($mail) {
  */
 function valid_url($url, $absolute = FALSE) {
   if ($absolute) {
-    return preg_match("/^(http|https|ftp):\/\/[a-z0-9\/:_\-_\.\?,~=#&%]+$/i", $url);
+    return preg_match("/^(http|https|ftp):\/\/[a-z0-9\/:_\-_\.\?,~=#&%\+]+$/i", $url);
   }
   else {
-    return preg_match("/^[a-z0-9\/:_\-_\.,]+$/i", $url);
+    return preg_match("/^[a-z0-9\/:_\-_\.,\+]+$/i", $url);
   }
 }