diff --git a/source.nix b/source.nix
index aa49062..ce58554 100644
--- a/source.nix
+++ b/source.nix
@@ -11,7 +11,7 @@ let
               then "buildbot"
               else "makefu";
   _file = <stockholm> + "/makefu/1systems/${name}/source.nix";
-  ref = "6778819"; # unstable @ 2017-11-14
+  ref = "3874de4"; # unstable @ 2017-12-08
                    # + do_sqlite3 ruby: 55a952be5b5
 
 in