diff --git a/management/univention-directory-notifier/univention-replicate-many b/management/univention-directory-notifier/univention-replicate-many
index 029663bc41..25e98256dd 100755
--- a/management/univention-directory-notifier/univention-replicate-many
+++ b/management/univention-directory-notifier/univention-replicate-many
@@ -54,7 +54,7 @@ fi
 
 dnfile="$1"
 
-if [ -n "$dnfile" ]; then
+if [ -z "$dnfile" ]; then
 	usage >&2
 	exit 1
 fi