diff --git a/addons/sale_management/models/sale_order.py b/addons/sale_management/models/sale_order.py
index 54c8ab0a530..35c5eda5756 100644
--- a/addons/sale_management/models/sale_order.py
+++ b/addons/sale_management/models/sale_order.py
@@ -202,13 +202,14 @@ class SaleOrderOption(models.Model):
         if not self.product_id:
             return
         product = self.product_id.with_context(lang=self.order_id.partner_id.lang)
-        self.price_unit = product.list_price
         self.name = product.get_product_multiline_description_sale()
         self.uom_id = self.uom_id or product.uom_id
-        pricelist = self.order_id.pricelist_id
-        if pricelist and product:
-            partner_id = self.order_id.partner_id.id
-            self.price_unit = pricelist.with_context(uom=self.uom_id.id).get_product_price(product, self.quantity, partner_id)
+        # To compute the dicount a so line is created in cache
+        values = self._get_values_to_add_to_order()
+        new_sol = self.env['sale.order.line'].new(values)
+        new_sol._onchange_discount()
+        self.discount = new_sol.discount
+        self.price_unit = new_sol._get_display_price(product)
 
     def button_add_to_order(self):
         self.add_option_to_order()