diff --git a/addons/sale/models/sale.py b/addons/sale/models/sale.py
index 2efa2c7d919..4cb02549b38 100644
--- a/addons/sale/models/sale.py
+++ b/addons/sale/models/sale.py
@@ -220,7 +220,10 @@ class SaleOrder(models.Model):
             if not order.company_id:
                 order.currency_rate = order.currency_id.with_context(date=order.date_order).rate or 1.0
                 continue
-            order.currency_rate = self.env['res.currency']._get_conversion_rate(order.company_id.currency_id, order.currency_id, order.company_id, order.date_order)
+            elif order.company_id.currency_id and order.currency_id:  # the following crashes if any one is undefined
+                order.currency_rate = self.env['res.currency']._get_conversion_rate(order.company_id.currency_id, order.currency_id, order.company_id, order.date_order)
+            else:
+                order.currency_rate = 1.0
 
     def _compute_access_url(self):
         super(SaleOrder, self)._compute_access_url()