diff --git a/ipv6/ar.cidr b/ipv6/ar.cidr
index 1d49faafa..2057550b1 100644
--- a/ipv6/ar.cidr
+++ b/ipv6/ar.cidr
@@ -775,7 +775,6 @@
 2803:9b40::/32
 2803:9b80::/32
 2803:9be0::/32
-2803:9c00::/32
 2803:9c10::/32
 2803:9c40::/32
 2803:9c80::/32
diff --git a/ipv6/co.cidr b/ipv6/co.cidr
index fc4f0b5c7..2e5d69b5a 100644
--- a/ipv6/co.cidr
+++ b/ipv6/co.cidr
@@ -134,6 +134,7 @@
 2801:16:d800::/48
 2801:16:f000::/48
 2801:16:f800::/48
+2801:17:400::/48
 2801:17:1800::/48
 2801:17:2800::/48
 2801:17:4000::/48