diff --git a/modules/sale_shipment_cost/sale.py b/modules/sale_shipment_cost/sale.py
index 25da0233a7..0a9701f981 100644
--- a/modules/sale_shipment_cost/sale.py
+++ b/modules/sale_shipment_cost/sale.py
@@ -395,6 +395,12 @@ class Sale(metaclass=PoolMeta):
             shipment.carrier = self.carrier
         return shipment
 
+    @classmethod
+    def copy(cls, sales, default=None):
+        default = default.copy() if default is not None else {}
+        default.setdefault('shipment_costs', None)
+        return super().copy(sales, default=default)
+
 
 class Line(metaclass=PoolMeta):
     __name__ = 'sale.line'