diff --git a/move.py b/move.py
index 5a9ed2410a..4dc3d9277d 100644
--- a/move.py
+++ b/move.py
@@ -474,10 +474,12 @@ class Move(Workflow, ModelSQL, ModelView):
         return ((from_type != 'storage' and to_type == 'storage')
             or (from_type == 'storage' and to_type != 'storage'))
 
-    @fields.depends('from_location')
+    @fields.depends('from_location', 'quantity')
     def on_change_with_assignation_required(self, name=None):
         if self.from_location:
-            return self.from_location.type in {'storage', 'view'}
+            return (
+                self.quantity
+                and self.from_location.type in {'storage', 'view'})
 
     @staticmethod
     def _get_shipment():
diff --git a/shipment.py b/shipment.py
index 718642a4de..3558155449 100644
--- a/shipment.py
+++ b/shipment.py
@@ -1249,6 +1249,9 @@ class ShipmentOut(ShipmentAssignMixin, Workflow, ModelSQL, ModelView):
     def pick(cls, shipments):
         pool = Pool()
         Move = pool.get('stock.move')
+        Move.delete([
+                m for s in shipments for m in s.inventory_moves
+                if m.state == 'staging'])
         Move.do([m for s in shipments for m in s.inventory_moves])
         cls._sync_inventory_to_outgoing(shipments, quantity=True)
 
@@ -1350,6 +1353,9 @@ class ShipmentOut(ShipmentAssignMixin, Workflow, ModelSQL, ModelView):
         Move = pool.get('stock.move')
         Date = pool.get('ir.date')
 
+        Move.delete([
+                m for s in shipments for m in s.outgoing_moves
+                if m.state == 'staging'])
         Move.do([m for s in shipments for m in s.outgoing_moves])
         cls.write([s for s in shipments if not s.effective_date], {
                 'effective_date': Date.today(),