diff --git a/ext/3rd-party-addons/global_discount/models/sale.py b/ext/3rd-party-addons/global_discount/models/sale.py
index d9d92b57..9e2d3a14 100755
--- a/ext/3rd-party-addons/global_discount/models/sale.py
+++ b/ext/3rd-party-addons/global_discount/models/sale.py
@@ -33,7 +33,7 @@ class SaleOrder(models.Model):
             if order.discount_type == 'fixed':
                 amount = order.discount_amount
             if order.discount_type == 'percentage':
-                amount = (order.amount_total * order.discount_percentage)/100
+                amount = (order.amount_untaxed * order.discount_percentage)/100
 
             # Create the Sale line
             Line.create({