diff --git base/univention-heimdal/conffiles/usr/share/univention-heimdal/check_cracklib.py base/univention-heimdal/conffiles/usr/share/univention-heimdal/check_cracklib.py
index 5808c3e795..28d416e85c 100644
--- base/univention-heimdal/conffiles/usr/share/univention-heimdal/check_cracklib.py
+++ base/univention-heimdal/conffiles/usr/share/univention-heimdal/check_cracklib.py
@@ -58,7 +58,7 @@ def main():
 		try:
 			pwdCheck.check(params['new-password'])
 			print('APPROVED')
-		except ValueError as exc:
+		except univention.password.CheckFailed as exc:
 			print(str(exc))