diff --git a/group_vars/all b/group_vars/all
index 2774a0a..16a8384 100644
--- a/group_vars/all
+++ b/group_vars/all
@@ -20,7 +20,7 @@ mail_domains:
 - ccc-regensburg.de
 mail_server: mail.binary-kitchen.de
 mailman_domain: lists.binary-kitchen.de
-mail_trusted: 213.166.246.0/28 2a02:958:0:f6::/124
+mail_trusted: 213.166.246.0/28 [2a02:958:0:f6::]/124
 mail_aliases:
 - "info@binary-kitchen.de	vorstand@binary-kitchen.de"
 - "lebercast@binary-kitchen.de	anti@binary-kitchen.de,dragonchaser@binary-kitchen.de,moepman@binary-kitchen.de,philmacfly@binary-kitchen.de,ralf@binary-kitchen.de"