diff --git a/ci-builds.nix b/ci-builds.nix
index 8bb649586..d29edac43 100644
--- a/ci-builds.nix
+++ b/ci-builds.nix
@@ -19,6 +19,7 @@ in with pkgs; [
   tools.cheddar
   tools.emacs
   web.cgit-taz
+  lisp.dns
   third_party.cgit
   third_party.git
   third_party.guile