diff --git a/include/functions.inc.php b/include/functions.inc.php
index d81d62727..195f7f00d 100644
--- a/include/functions.inc.php
+++ b/include/functions.inc.php
@@ -978,7 +978,7 @@ function l10n($key)
 {
   global $lang, $conf;
 
-  if ( ($val=@$lang[$key]) == null)
+  if ( ($val=@$lang[$key]) === null)
   {
     if ($conf['debug_l10n'] and !isset($lang[$key]) and !empty($key))
     {