diff --git a/trytond/ir/ui/view.py b/trytond/ir/ui/view.py
index 799edc2772..a69653d5cd 100644
--- a/trytond/ir/ui/view.py
+++ b/trytond/ir/ui/view.py
@@ -29,8 +29,11 @@ class View(OSV):
         'module': lambda obj, cursor, user, context: context.get('module', ''),
     }
     _order = "priority"
+    _constraints = [
+        ('check_xml', 'Invalid XML for View Architecture!', ['arch'])
+    ]
 
-    def _check_xml(self, cursor, user, ids):
+    def check_xml(self, cursor, user, ids):
         "Check XML"
         views = self.browse(cursor, user, ids)
         cursor.execute('SELECT id, name, src FROM ir_translation ' \
@@ -100,10 +103,6 @@ class View(OSV):
                     (view.model, 'view') + tuple(strings))
         return True
 
-    _constraints = [
-        (_check_xml, 'Invalid XML for View Architecture!', ['arch'])
-    ]
-
     def unlink(self, cursor, user, ids, context=None):
 
         if isinstance(ids, (int, long)):
diff --git a/trytond/osv/orm.py b/trytond/osv/orm.py
index 3354397081..bc46c8bb78 100644
--- a/trytond/osv/orm.py
+++ b/trytond/osv/orm.py
@@ -1177,7 +1177,7 @@ class ORM(object):
         field_error = []
         field_err_str = []
         for field in self._constraints:
-            if not field[0](self, cursor, user, ids):
+            if not getattr(self, field[0])(cursor, user, ids):
                 if len(field) > 1:
                     field_error += field[2]
                 field_err_str.append(field[1])
diff --git a/trytond/webdav/webdav.py b/trytond/webdav/webdav.py
index fc3490b281..3601e991a8 100644
--- a/trytond/webdav/webdav.py
+++ b/trytond/webdav/webdav.py
@@ -25,13 +25,9 @@ class Directory(OSV):
         ('name_parent_uniq', 'UNIQUE (name, parent)',
             'The directory name must be unique inside a directory!'),
     ]
-
-    def check_recursion(self, cursor, user, ids, parent=None):
-        return super(Directory, self).check_recursion(cursor, user, ids,
-                parent='parent')
-
+    _parent_name = 'parent'
     _constraints = [
-        (check_recursion,
+        ('check_recursion',
             'Error! You can not create recursive directories.', ['parent']),
     ]
     ext2mime = {