diff --git a/htdocs/install/mysql/migration/12.0.0-13.0.0.sql b/htdocs/install/mysql/migration/12.0.0-13.0.0.sql
index 35f2e4e8a54..7dfccac5beb 100644
--- a/htdocs/install/mysql/migration/12.0.0-13.0.0.sql
+++ b/htdocs/install/mysql/migration/12.0.0-13.0.0.sql
@@ -312,6 +312,3 @@ ALTER TABLE llx_inventorydet ADD UNIQUE uk_inventorydet(fk_inventory, fk_warehou
 
 ALTER TABLE llx_product_attribute ADD COLUMN ref_ext varchar(255) AFTER ref;
 ALTER TABLE llx_product_attribute_combination ADD COLUMN variation_ref_ext varchar(255) AFTER variation_weight;
-
-ALTER TABLE llx_product_attribute ADD COLUMN ref_ext varchar(255) AFTER ref;
-ALTER TABLE llx_product_attribute_combination ADD COLUMN variation_ref_ext varchar(255) AFTER variation_weight;