diff --git a/openerp/addons/base/module/module_data.xml b/openerp/addons/base/module/module_data.xml
index c6d1ca17996..59d7d40137d 100644
--- a/openerp/addons/base/module/module_data.xml
+++ b/openerp/addons/base/module/module_data.xml
@@ -143,7 +143,7 @@
         </record>
 
         <record model="res.groups" id="group_multi_company">
-            <field name="category_id" ref="module_category_extra"/>
+            <field name="category_id" ref="module_category_usability"/>
         </record>
 
         <record model="res.groups" id="group_light_multi_company">
diff --git a/openerp/addons/base/res/res_users.py b/openerp/addons/base/res/res_users.py
index b35a40fb28d..e81d53707ff 100644
--- a/openerp/addons/base/res/res_users.py
+++ b/openerp/addons/base/res/res_users.py
@@ -781,7 +781,7 @@ class groups_view(osv.osv):
             xml1.append(E.separator(string=_('Application'), colspan="2"))
             for app, kind, gs in self.get_groups_by_application(cr, uid, user_context):
                 # hide groups in category 'Hidden' (except to group_no_one)
-                attrs = {'groups': 'base.group_no_one'} if app and app.xml_id == 'base.module_category_hidden' else {}
+                attrs = {'groups': 'base.group_no_one'} if app and (app.xml_id == 'base.module_category_hidden' or app.xml_id == 'base.module_category_extra') else {}
                 if kind == 'selection':
                     # application name with a selection field
                     field_name = name_selection_groups(map(int, gs))