diff --git a/install-dev/upgrade/sql/1.5.0.12.sql b/install-dev/upgrade/sql/1.5.0.12.sql
index b76b1c0c5..eb6865996 100644
--- a/install-dev/upgrade/sql/1.5.0.12.sql
+++ b/install-dev/upgrade/sql/1.5.0.12.sql
@@ -62,3 +62,4 @@ UPDATE `PREFIX_tab` SET `class_name`="AdminShopGroup" WHERE class_name="AdminGro
 
 /* PHP:p15012_add_missing_columns(); */;
 
+UPDATE `PREFIX_specific_price` SET `price` = -1 WHERE `price` = 0;
\ No newline at end of file