diff --git a/services/univention-s4-connector/modules/univention/s4connector/s4/main.py b/services/univention-s4-connector/modules/univention/s4connector/s4/main.py
index 024bc1f479..c779c652d2 100755
--- a/services/univention-s4-connector/modules/univention/s4connector/s4/main.py
+++ b/services/univention-s4-connector/modules/univention/s4connector/s4/main.py
@@ -35,6 +35,7 @@
 from __future__ import print_function
 import os
 import imp
+import pprint
 import signal
 import sys
 import time
@@ -277,6 +278,8 @@ def main():
 	if options.daemonize:
 		daemon(lock_file)
 	f = bind_stdout()
+	pp = pprint.PrettyPrinter(indent=4, width=250)
+	print('s4_mapping = %s' % (pp.pformat(mapping.s4_mapping),))
 
 	while True:
 		try: