diff --git a/stock.py b/stock.py
index 7c17be834a..7e1919dafe 100644
--- a/stock.py
+++ b/stock.py
@@ -385,6 +385,8 @@ class ShipmentDrop(Workflow, ModelSQL, ModelView):
         else:
             default = default.copy()
         default.setdefault('moves', None)
+        default.setdefault('supplier_moves', None)
+        default.setdefault('customer_moves', None)
         return super(ShipmentDrop, cls).copy(shipments, default=default)
 
     @classmethod