diff --git a/hosts/knot/default.nix b/hosts/knot/default.nix
index bf71240e..7f7d097b 100644
--- a/hosts/knot/default.nix
+++ b/hosts/knot/default.nix
@@ -50,6 +50,7 @@
           id = "axfr";
           address = [
             # INWX
+            # TODO: drop when c3d2.social migrated off
             "2a0a:c980::53/128"
             # Inbert
             "2001:67c:1400:2240::1/128"