diff --git a/install-new/upgrade/php/add_column_orders_reference_if_not_exists.php b/install-new/upgrade/php/add_column_orders_reference_if_not_exists.php
index 5919f28f5..80fa4415b 100644
--- a/install-new/upgrade/php/add_column_orders_reference_if_not_exists.php
+++ b/install-new/upgrade/php/add_column_orders_reference_if_not_exists.php
@@ -29,6 +29,5 @@ function add_column_orders_reference_if_not_exists()
 {
 	$column = Db::getInstance()->executeS('SHOW FIELDS FROM `'._DB_PREFIX_.'orders` LIKE "reference"');
 	if (empty($column))
-		return Db::getInstance()->execute('ALTER TABLE `PREFIX_orders` ADD COLUMN `reference` varchar(9) AFTER `id_order`');
-	return true;
+		return Db::getInstance()->execute('ALTER TABLE `'._DB_PREFIX_.'orders` ADD COLUMN `reference` varchar(9) AFTER `id_order`');
 }
diff --git a/install-new/upgrade/php/generate_order_reference.php b/install-new/upgrade/php/generate_order_reference.php
index 4245f9b1f..193083abf 100644
--- a/install-new/upgrade/php/generate_order_reference.php
+++ b/install-new/upgrade/php/generate_order_reference.php
@@ -2,6 +2,7 @@
 
 function generate_order_reference()
 {
+	$res = true;
 	// Get all orders
 	$orders = Db::getInstance()->executeS('SELECT id_order FROM '._DB_PREFIX_.'orders');
 	foreach ($orders as $order)
@@ -9,9 +10,10 @@ function generate_order_reference()
 		$random_ref = '';
 		for ($i = 0, $passwd = ''; $i < 9; $i++)
 			$random_ref .= substr('ABCDEFGHIJKLMNOPQRSTUVWXYZ', mt_rand(0,25), 1);
-		Db::getInstance()->execute('
+		$res &= Db::getInstance()->execute('
 			UPDATE '._DB_PREFIX_.'orders
 			SET reference = \''.$random_ref.'\'
 			WHERE id_order = '.(int)$order['id_order']);
 	}
+	return $res;
 }
diff --git a/install-new/upgrade/php/update_mailalerts_add_column_idshop.php b/install-new/upgrade/php/update_mailalerts_add_column_idshop.php
index c4e98a90a..318f3a366 100644
--- a/install-new/upgrade/php/update_mailalerts_add_column_idshop.php
+++ b/install-new/upgrade/php/update_mailalerts_add_column_idshop.php
@@ -9,9 +9,12 @@ function update_mailalerts_add_column_idshop()
 	$id_mailalerts = Db::getInstance()->getValue('SELECT id_module FROM  `'._DB_PREFIX_.'module` WHERE name = "mailalerts"');
 
 	if($id_mailalerts)
+	{
 		$res = Db::getInstance()->execute('ALTER TABLE `'._DB_PREFIX_.'mailalert_customer_oos` ADD COLUMN `id_shop` int(11) NOT NULL default "0" AFTER `id_customer`');
-	if ($res)
-		return true;
-	else
-		return array('error' => 1, 'msg' => sprintf('unable to create column id_shop (%s)', Db::getInstance ()->getMsgError()));
-}
\ No newline at end of file
+		if ($res)
+			return true;
+		else
+			return array('error' => 1, 'msg' => sprintf('unable to create column id_shop (%s)', Db::getInstance ()->getMsgError()));
+	}
+	return true;
+}