diff --git a/install-dev/upgrade/php/p1540_add_missing_columns.php b/install-dev/upgrade/php/p1540_add_missing_columns.php
index b63af1a71..95a3b6ab1 100644
--- a/install-dev/upgrade/php/p1540_add_missing_columns.php
+++ b/install-dev/upgrade/php/p1540_add_missing_columns.php
@@ -43,12 +43,14 @@ function p1540_add_missing_columns()
 	if ($id_module)
 	{
 		$list_fields = Db::getInstance()->executeS('SHOW FIELDS FROM `'._DB_PREFIX_.'layered_product_attribute`');
-		foreach ($list_fields as $k => $field)
-			$list_fields[$k] = $field['Field'];
-
-		if (!in_array('id_shop', $list_fields))
-			if (!Db::getInstance()->execute('ALTER TABLE `'._DB_PREFIX_.'layered_product_attribute` ADD `id_shop` INT( 10 ) UNSIGNED NOT NULL DEFAULT "1" AFTER `id_attribute_group`'))
-				$errors[] = Db::getInstance()->getMsgError();				
+		if(is_array($list_fields))
+		{
+			foreach ($list_fields as $k => $field)
+				$list_fields[$k] = $field['Field'];
+			if (!in_array('id_shop', $list_fields))
+				if (!Db::getInstance()->execute('ALTER TABLE `'._DB_PREFIX_.'layered_product_attribute` ADD `id_shop` INT( 10 ) UNSIGNED NOT NULL DEFAULT "1" AFTER `id_attribute_group`'))
+					$errors[] = Db::getInstance()->getMsgError();
+		}			
 	}
 	
 	$key_exists = Db::getInstance()->executeS('SHOW INDEX FROM `'._DB_PREFIX_.'stock_available` WHERE KEY_NAME = "product_sqlstock"');;