diff --git a/ipv6/in.cidr b/ipv6/in.cidr
index 781cdc3fe..cb14511de 100644
--- a/ipv6/in.cidr
+++ b/ipv6/in.cidr
@@ -1054,6 +1054,7 @@
 2001:df4:d780::/48
 2001:df4:d840::/48
 2001:df4:d900::/48
+2001:df4:dac0::/48
 2001:df4:db00::/46
 2001:df4:e000::/48
 2001:df4:ef80::/48