diff --git a/include/functions_rate.inc.php b/include/functions_rate.inc.php
index d0319bd5c..b8d4a6256 100644
--- a/include/functions_rate.inc.php
+++ b/include/functions_rate.inc.php
@@ -34,6 +34,7 @@ function rate_picture($image_id, $rate)
 
   if (!isset($rate)
       or !$conf['rate']
+      or !preg_match('/^[0-9]+$/', $rate)
       or !in_array($rate, $conf['rate_items']))
   {
     return false;