diff --git a/dblayeroo.php b/dblayeroo.php
index b3633b5..ac3974b 100644
--- a/dblayeroo.php
+++ b/dblayeroo.php
@@ -2632,7 +2632,7 @@ class dblayeroo
       $this->DBException ("Invalid values to normalize : not an array", 406);
     foreach ($values as $key => $val)
     {
-      if ($val !== null)
+      if ($val !== null && ! is_array ($val))
         $values[$key] = trim ($val);
     }
     return $values;