diff --git a/exceptions.py b/exceptions.py
index 2933239c6c..de1ece4150 100644
--- a/exceptions.py
+++ b/exceptions.py
@@ -8,6 +8,10 @@ class AssignError(UserError):
     pass
 
 
+class MoveValidationError(ValidationError):
+    pass
+
+
 class LocationValidationError(ValidationError):
     pass
 
diff --git a/product.py b/product.py
index a1836581b2..d0e6052b35 100644
--- a/product.py
+++ b/product.py
@@ -285,13 +285,16 @@ class Product(StockMixin, object, metaclass=PoolMeta):
             ('state', '=', 'done'),
             ]
 
+    @classmethod
+    def _domain_storage_quantity(cls):
+        "Returns the domain for locations to use in cost computation"
+        return [('type', '=', 'storage')]
+
     def _get_storage_quantity(self, date=None):
         pool = Pool()
         Location = pool.get('stock.location')
 
-        locations = Location.search([
-            ('type', '=', 'storage'),
-            ])
+        locations = Location.search(self._domain_storage_quantity())
         if not date:
             date = datetime.date.today()
         location_ids = [l.id for l in locations]