diff --git a/install-dev/upgrade/php/update_mailalerts_add_column_idshop.php b/install-dev/upgrade/php/update_mailalerts_add_column_idshop.php
index 9920567a1..c79407dec 100644
--- a/install-dev/upgrade/php/update_mailalerts_add_column_idshop.php
+++ b/install-dev/upgrade/php/update_mailalerts_add_column_idshop.php
@@ -31,6 +31,7 @@
 function update_mailalerts_add_column_idshop()
 {
 	$installed = Db::getInstance()->getValue('SELECT id_module FROM  `'._DB_PREFIX_.'module` WHERE name = "mailalerts"');
+	$installed &= Db::getInstance()->getValue('SHOW TABLES LIKE "'._DB_PREFIX_.'mailalert_customer_oos"');
 	if ($installed && !Db::getInstance()->execute('ALTER TABLE `'._DB_PREFIX_.'mailalert_customer_oos` ADD COLUMN `id_shop` int(11) NOT NULL default "0" AFTER `id_customer`'))
 		return array('error' => 1, 'msg' => sprintf('unable to create column id_shop (%s)', Db::getInstance ()->getMsgError()));
 	return true;