diff --git a/ucs-school-lib/python/models/base.py b/ucs-school-lib/python/models/base.py
index cbf9795..4141b6b 100644
--- a/ucs-school-lib/python/models/base.py
+++ b/ucs-school-lib/python/models/base.py
@@ -724,6 +724,7 @@ class UCSSchoolHelperAbstractClass(object):
 					udm_value = None
 				attrs[name] = udm_value
 		obj = cls(**deepcopy(attrs))
+		obj.custom_dn = udm_obj.dn  # FIXME: Bug #40940: setting this causes the object to not being moveable
 		obj.set_dn(udm_obj.dn)
 		obj._udm_obj_searched = True
 		obj._udm_obj = udm_obj
@@ -778,7 +779,7 @@ class UCSSchoolHelperAbstractClass(object):
 			raise noObject('Wrong objectClass: %r is not a %r.' % (dn, cls.__name__))
 		obj = cls.from_udm_obj(udm_obj, school, lo)
 		if obj:
-			obj.custom_dn = dn  # FIXME: this breaks some things. we better have to set old_dn!
+			obj.custom_dn = dn  # FIXME: Bug #40940: this breaks some things. we better have to set old_dn!
 			return obj
 
 	@classmethod