diff --git a/htdocs/core/class/menubase.class.php b/htdocs/core/class/menubase.class.php
index 0daf4fe56da..17ada096fd1 100644
--- a/htdocs/core/class/menubase.class.php
+++ b/htdocs/core/class/menubase.class.php
@@ -1,6 +1,7 @@
 <?php
 /* Copyright (C) 2007-2009	Laurent Destailleur	<eldy@users.sourceforge.net>
  * Copyright (C) 2009-2012	Regis Houssin		<regis.houssin@capnetworks.com>
+ * Copyright (C) 2018       Frédéric France     <frederic.france@netlogic.fr>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -59,15 +60,18 @@ class Menubase
     public $fk_menu;
 
     /**
-     * @var int ID
+     * @var string fk_mainmenu
      */
     public $fk_mainmenu;
 
     /**
-     * @var int ID
+     * @var string fk_leftmenu
      */
     public $fk_leftmenu;
 
+    /**
+     * @var int position
+     */
     public $position;
     public $url;
     public $target;
@@ -111,10 +115,10 @@ class Menubase
         $this->type=trim($this->type);
         $this->mainmenu=trim($this->mainmenu);
         $this->leftmenu=trim($this->leftmenu);
-        $this->fk_menu=trim($this->fk_menu);          // If -1, fk_mainmenu and fk_leftmenu must be defined
+        $this->fk_menu = (int) $this->fk_menu;          // If -1, fk_mainmenu and fk_leftmenu must be defined
         $this->fk_mainmenu=trim($this->fk_mainmenu);
         $this->fk_leftmenu=trim($this->fk_leftmenu);
-        $this->position=trim($this->position);
+        $this->position = (int) $this->position;
         $this->url=trim($this->url);
         $this->target=trim($this->target);
         $this->titre=trim($this->titre);
@@ -155,7 +159,7 @@ class Menubase
         $sql = "SELECT count(*)";
         $sql.= " FROM ".MAIN_DB_PREFIX."menu";
         $sql.= " WHERE menu_handler = '".$this->db->escape($this->menu_handler)."'";
-        $sql.= " AND fk_menu = ".((int) $this->db->escape($this->fk_menu));
+        $sql.= " AND fk_menu = ".((int) $this->fk_menu);
         $sql.= " AND position = ".((int) $this->position);
         $sql.= " AND url = '".$this->db->escape($this->url)."'";
         $sql.= " AND entity = ".$conf->entity;
@@ -252,10 +256,10 @@ class Menubase
         $this->type=trim($this->type);
         $this->mainmenu=trim($this->mainmenu);
         $this->leftmenu=trim($this->leftmenu);
-        $this->fk_menu=trim($this->fk_menu);
+        $this->fk_menu = (int) $this->fk_menu;
         $this->fk_mainmenu=trim($this->fk_mainmenu);
         $this->fk_leftmenu=trim($this->fk_leftmenu);
-        $this->position=trim($this->position);
+        $this->position = (int) $this->position;
         $this->url=trim($this->url);
         $this->target=trim($this->target);
         $this->titre=trim($this->titre);
@@ -274,7 +278,7 @@ class Menubase
         $sql.= " type='".$this->db->escape($this->type)."',";
         $sql.= " mainmenu='".$this->db->escape($this->mainmenu)."',";
         $sql.= " leftmenu='".$this->db->escape($this->leftmenu)."',";
-        $sql.= " fk_menu='".$this->db->escape($this->fk_menu)."',";
+        $sql.= " fk_menu=".$this->fk_menu.",";
         $sql.= " fk_mainmenu=".($this->fk_mainmenu?"'".$this->db->escape($this->fk_mainmenu)."'":"null").",";
         $sql.= " fk_leftmenu=".($this->fk_leftmenu?"'".$this->db->escape($this->fk_leftmenu)."'":"null").",";
         $sql.= " position=".($this->position > 0 ? $this->position : 0).",";