diff --git a/management/univention-directory-manager-modules/modules/univention/admin/__init__.py b/management/univention-directory-manager-modules/modules/univention/admin/__init__.py
index 4c8da83..4e4b8d0 100644
--- a/management/univention-directory-manager-modules/modules/univention/admin/__init__.py
+++ b/management/univention-directory-manager-modules/modules/univention/admin/__init__.py
@@ -33,6 +33,7 @@
 import types
 import sys
 import re
+import copy
 import univention.config_registry
 import univention.debug
 
@@ -190,7 +191,8 @@ def __init__(self, short_description='', long_description='', syntax=None,
 		self.may_change=may_change
 		self.identifies=identifies
 		self.unique=unique
-		self.base_default=default
+		self.__base_default=copy.copy(default)
+		self.base_default=copy.copy(self.__base_default)
 		self.dontsearch=dontsearch
 		self.show_in_lists=show_in_lists
 		self.editable=editable
@@ -210,9 +212,10 @@ def new(self):
 			return None
 
 	def _replace( self, res, object ):
-		return pattern_replace( res, object )
+		return pattern_replace( copy.copy(res), object )
 
 	def default(self, object):
+		self.base_default = copy.copy(self.__base_default)
 		if not object.set_defaults:
 			if self.multivalue:
 				return []