diff --git a/lass/1systems/blue/source.nix b/lass/1systems/blue/source.nix
new file mode 100644
index 000000000..8f748ab8f
--- /dev/null
+++ b/lass/1systems/blue/source.nix
@@ -0,0 +1,11 @@
+{ lib, pkgs, ... }:
+{
+  nixpkgs = lib.mkForce {
+    file = toString (pkgs.fetchFromGitHub {
+      owner = "nixos";
+      repo = "nixpkgs";
+      rev = (lib.importJSON ../../../krebs/nixpkgs.json).rev;
+      sha256 = (lib.importJSON ../../../krebs/nixpkgs.json).sha256;
+    });
+  };
+}