diff --git a/tryton/modules/stock_lot/stock.py b/tryton/modules/stock_lot/stock.py
index 3e93c4e57c..734018dbe8 100644
--- a/tryton/modules/stock_lot/stock.py
+++ b/tryton/modules/stock_lot/stock.py
@@ -78,7 +78,7 @@ class Lot(DeactivableMixin, ModelSQL, ModelView, LotMixin, StockMixin):
         'get_quantity', searcher='search_quantity')
     default_uom = fields.Function(
         fields.Many2One('product.uom', "Default UOM"),
-        'on_change_with_default_uom')
+        'on_change_with_default_uom', searcher='search_default_uom')
     default_uom_digits = fields.Function(fields.Integer("Default Unit Digits"),
         'on_change_with_default_uom_digits')

@@ -152,6 +152,11 @@ class Lot(DeactivableMixin, ModelSQL, ModelView, LotMixin, StockMixin):
     def downward_traces(cls, lots):
         pass

+    @classmethod
+    def search_default_uom(cls, name, clause):
+        nested = clause[0][len(name):]
+        return [('product.' + name + nested, *clause[1:])]
+

 class LotTrace(ModelSQL, ModelView):
     "Lot Trace"