diff --git a/trytond/model/model.py b/trytond/model/model.py
index f58242d98a..446ed49452 100644
--- a/trytond/model/model.py
+++ b/trytond/model/model.py
@@ -27,6 +27,7 @@ class Model(WarningErrorMixin, URLMixin):
 
     def _reset_columns(self):
         self.__columns = None
+        self.__defaults = None
 
     def _getcolumns(self):
         if self.__columns: