diff --git a/management/univention-directory-manager-modules/modules/univention/admin/handlers/__init__.py b/management/univention-directory-manager-modules/modules/univention/admin/handlers/__init__.py
index 9a2ed9e..8d52201 100644
--- a/management/univention-directory-manager-modules/modules/univention/admin/handlers/__init__.py
+++ b/management/univention-directory-manager-modules/modules/univention/admin/handlers/__init__.py
@@ -553,7 +553,7 @@ def _not_implemented_error(self, *args, **kwargs):
 
 class simpleLdap(base):
 
-	def __init__(self, co, lo, position, dn='', superordinate=None, attributes = [] ):
+	def __init__(self, co, lo, position, dn='', superordinate=None, attributes=None):
 		global s4connector_present
 		global s4connector_search
 
@@ -575,10 +575,14 @@ def __init__(self, co, lo, position, dn='', superordinate=None, attributes = []
 					s4connector_present = False
 		self.s4connector_present = s4connector_present
 
+		self.oldattr = {}
 		if attributes:
 			self.oldattr = attributes
-		else:
-			self.oldattr=self.lo.get(self.dn)
+		elif self.dn:
+			try:
+				self.oldattr = self.lo.get(self.dn, required=True)
+			except ldap.NO_SUCH_OBJECT:
+				raise univention.admin.uexceptions.noObject(self.dn)
 		if self.oldattr:
 			self._exists = True
 			oldinfo=univention.admin.mapping.mapDict(self.mapping, self.oldattr)