diff --git a/third_party/lisp/routes.nix b/third_party/lisp/routes.nix
index fc7d4e306..48a95c87a 100644
--- a/third_party/lisp/routes.nix
+++ b/third_party/lisp/routes.nix
@@ -4,12 +4,7 @@ let
 
   src = pkgs.applyPatches {
     name = "routes-source";
-    src = pkgs.fetchFromGitHub {
-      owner = "archimag";
-      repo = "cl-routes";
-      rev = "1b79e85aa653e1ec87e21ca745abe51547866fa9";
-      sha256 = "1zpk3cp2v8hm50ppjl10yxr437vv4552r8hylvizglzrq2ibsbr1";
-    };
+    src = pkgs.srcOnly pkgs.sbcl.pkgs.routes;
 
     patches = [
       (pkgs.fetchpatch {