diff --git a/ipv6/mx.cidr b/ipv6/mx.cidr
index 8a161278e..f0b42d42d 100644
--- a/ipv6/mx.cidr
+++ b/ipv6/mx.cidr
@@ -68,7 +68,7 @@
 2801:c4:240::/44
 2801:c4:250::/47
 2801:c4:253::/48
-2801:c4:254::/48
+2801:c4:254::/47
 2801:c4:259::/48
 2801:c4:25a::/47
 2801:c4:25c::/47