diff --git a/services/univention-ad-connector/modules/univention/connector/__init__.py b/services/univention-ad-connector/modules/univention/connector/__init__.py
index d4ae93b60d..01a6dfe38f 100644
--- a/services/univention-ad-connector/modules/univention/connector/__init__.py
+++ b/services/univention-ad-connector/modules/univention/connector/__init__.py
@@ -1423,7 +1423,7 @@ class ucs:
 					retlist.append(l.lower())
 				return retlist
 			else:
-				return elements
+				return elements.lower()
 
 		def dict_lower(dict):
 			if isinstance(dict, type({})):