diff --git a/ipv6/mx.cidr b/ipv6/mx.cidr
index 1eadfd3b2..483ba711a 100644
--- a/ipv6/mx.cidr
+++ b/ipv6/mx.cidr
@@ -70,6 +70,7 @@
 2801:c4:259::/48
 2801:c4:25a::/48
 2801:c4:25c::/48
+2801:c4:25f::/48
 2801:c4:260::/44
 2801:c4:270::/47
 2801:c4:278::/46