diff --git a/install-dev/upgrade/php/add_new_tab.php b/install-dev/upgrade/php/add_new_tab.php
index 246bb0ac7..602b2477a 100644
--- a/install-dev/upgrade/php/add_new_tab.php
+++ b/install-dev/upgrade/php/add_new_tab.php
@@ -24,12 +24,10 @@
 *  International Registered Trademark & Property of PrestaShop SA
 */
 
-function add_new_tab($className, $name, $id_parent, $returnId = false, $parentTab)
+function add_new_tab($className, $name, $id_parent, $returnId = false, $parentTab = null)
 {
-	if (isset($parentTab) && !empty($parentTab) && (is_null($id_parent) || empty($id_parent)))
+	if (!is_null($parentTab) && !empty($parentTab))
 		$id_parent = (int)Db::getInstance()->getValue('SELECT `id_tab` FROM `'._DB_PREFIX_.'tab` WHERE `class_name` = \''.pSQL($parentTab).'\'');
-	if (!$id_parent)
-		return false;
 	
 	$array = array();
 	foreach (explode('|', $name) AS $item)
diff --git a/install-dev/upgrade/sql/1.5.5.0.sql b/install-dev/upgrade/sql/1.5.5.0.sql
index fe1c1da49..934492867 100644
--- a/install-dev/upgrade/sql/1.5.5.0.sql
+++ b/install-dev/upgrade/sql/1.5.5.0.sql
@@ -22,6 +22,5 @@ CHANGE `module_name` `module_name` VARCHAR(64) NULL DEFAULT NULL;
 
 ALTER TABLE `PREFIX_log` ADD `id_employee` INT(10) UNSIGNED NULL AFTER `object_id`;
 
-@id_parent = (SELECT IFNULL(id_tab, 1) FROM `PREFIX_tab` WHERE `class_name` = 'AdminPriceRule' LIMIT 1);
+SET @id_parent = (SELECT IFNULL(id_tab, 1) FROM `PREFIX_tab` WHERE `class_name` = 'AdminPriceRule' LIMIT 1);
 UPDATE `PREFIX_tab` SET id_parent = @id_parent WHERE `id_parent` = 1 AND `class_name` = 'AdminMarketing' LIMIT 1;
-