diff --git a/include/dblayer/functions_mysqli.inc.php b/include/dblayer/functions_mysqli.inc.php
index 84390f1c8..68ed83f2a 100644
--- a/include/dblayer/functions_mysqli.inc.php
+++ b/include/dblayer/functions_mysqli.inc.php
@@ -230,7 +230,7 @@ function pwg_db_real_escape_string($s)
 {
   global $mysqli;
   
-  return $mysqli->real_escape_string($s);
+  return isset($s) ? $mysqli->real_escape_string($s) : null;
 }
 
 function pwg_db_insert_id()
diff --git a/include/functions_user.inc.php b/include/functions_user.inc.php
index 6f9325144..ea223169a 100644
--- a/include/functions_user.inc.php
+++ b/include/functions_user.inc.php
@@ -919,14 +919,9 @@ function create_user_infos($user_ids, $override_values=null)
       {
         $status = 'normal';
       }
-
-      $pwg_db_real_escape_string = function($str)
-      {
-        return isset($str) ? pwg_db_real_escape_string($str) : '';
-      };
       
       $insert = array_merge(
-        array_map($pwg_db_real_escape_string, $default_user),
+        array_map('pwg_db_real_escape_string', $default_user),
         array(
           'user_id' => $user_id,
           'status' => $status,