diff --git a/source.nix b/source.nix
index 647803f..c22c82f 100644
--- a/source.nix
+++ b/source.nix
@@ -13,8 +13,9 @@ let
               then "buildbot"
               else "makefu";
   _file = <stockholm> + "/makefu/1systems/${name}/source.nix";
-  ref = "3e8d708"; # nixos-17.09 @ 2018-01-05
+  ref = "0f19bee"; # nixos-17.09 @ 2018-01-05
                    # + do_sqlite3 ruby: 55a952be5b5
+                   # + signal: 0f19beef3
 
 in
   evalSource (toString _file) [