diff --git a/odoo/addons/base/models/res_config.py b/odoo/addons/base/models/res_config.py
index 3642bc11280..7576568ddd6 100644
--- a/odoo/addons/base/models/res_config.py
+++ b/odoo/addons/base/models/res_config.py
@@ -441,7 +441,7 @@ class ResConfigSettings(models.TransientModel, ResConfigModuleInstallationMixin)
                 self._onchange_methods[name].append(method)
 
     @api.model
-    def _get_classified_fields(self):
+    def _get_classified_fields(self, fnames=None):
         """ return a dictionary with the fields classified by category::
 
                 {   'default': [('default_foo', 'model', 'foo'), ...],
@@ -454,9 +454,12 @@ class ResConfigSettings(models.TransientModel, ResConfigModuleInstallationMixin)
         IrModule = self.env['ir.module.module']
         Groups = self.env['res.groups']
         ref = self.env.ref
+        if fnames is None:
+            fnames = self._fields.keys()
 
         defaults, groups, modules, configs, others = [], [], [], [], []
-        for name, field in self._fields.items():
+        for name in fnames:
+            field = self._fields[name]
             if name.startswith('default_'):
                 if not hasattr(field, 'default_model'):
                     raise Exception("Field %s without attribute 'default_model'" % field)
@@ -493,7 +496,7 @@ class ResConfigSettings(models.TransientModel, ResConfigModuleInstallationMixin)
     def default_get(self, fields):
         IrDefault = self.env['ir.default']
         IrConfigParameter = self.env['ir.config_parameter'].sudo()
-        classified = self._get_classified_fields()
+        classified = self._get_classified_fields(fields)
 
         res = super(ResConfigSettings, self).default_get(fields)