diff --git base/univention-python/modules/uldap.py base/univention-python/modules/uldap.py
index 272f5d194b..259b7de12e 100644
--- base/univention-python/modules/uldap.py
+++ base/univention-python/modules/uldap.py
@@ -175,9 +175,10 @@ def getMachineConnection(start_tls=2, decode_ignorelist=[], ldap_master=True, se
 		# Connect to ldap/server/name
 		port = int(ucr.get('ldap/server/port', '7389'))
 		servers = [ucr.get('ldap/server/name')]
-		servers += ucr.get('ldap/server/addition','').split()
+		additional_servers = ucr.get('ldap/server/addition', '').split()
 		if random_server:
-			random.shuffle(servers)
+			random.shuffle(additional_servers)
+		servers.extend(additional_servers)
 		for server in servers:
 			try:
 				return access(host=server, port=port, base=ucr['ldap/base'], binddn=ucr['ldap/hostdn'], bindpw=bindpw, start_tls=start_tls, decode_ignorelist=decode_ignorelist, reconnect=reconnect)