diff --git a/htdocs/categories/class/categorie.class.php b/htdocs/categories/class/categorie.class.php
index 67cd2a4f5e0..56f26eb2dd9 100644
--- a/htdocs/categories/class/categorie.class.php
+++ b/htdocs/categories/class/categorie.class.php
@@ -781,7 +781,8 @@ class Categorie extends CommonObject
 
 		$objs = array();
 
-		$obj = new $this->MAP_OBJ_CLASS[$type]($this->db);
+		$tmpclass = $this->MAP_OBJ_CLASS[$type];
+		$obj = new $tmpclass($this->db);
 
 		$sql = "SELECT c.fk_".$this->MAP_CAT_FK[$type];
 		$sql .= " FROM ".MAIN_DB_PREFIX."categorie_".$this->MAP_CAT_TABLE[$type]." as c";