diff --git a/addons/purchase_stock/models/stock.py b/addons/purchase_stock/models/stock.py
index 401e0771400..4ef9dad4bda 100644
--- a/addons/purchase_stock/models/stock.py
+++ b/addons/purchase_stock/models/stock.py
@@ -47,7 +47,7 @@ class StockMove(models.Model):
                 price_unit *= line.product_uom.factor / line.product_id.uom_id.factor
             if order.currency_id != order.company_id.currency_id:
                 price_unit = order.currency_id._convert(
-                    price_unit, order.company_id.currency_id, order.company_id, order.date_order or fields.Date.today(), round=False)
+                    price_unit, order.company_id.currency_id, order.company_id, self.date, round=False)
             return price_unit
         return super(StockMove, self)._get_price_unit()