diff --git a/ipv6/in.cidr b/ipv6/in.cidr
index 33acf22c2..40a1c2edf 100644
--- a/ipv6/in.cidr
+++ b/ipv6/in.cidr
@@ -202,7 +202,7 @@
 2001:df0:c640::/48
 2001:df0:c740::/48
 2001:df0:c780::/48
-2001:df0:c7c0::/48
+2001:df0:c7c0::/47
 2001:df0:c9c0::/48
 2001:df0:cb40::/48
 2001:df0:cb80::/48