diff --git a/build.nix b/build.nix
index 8a5264d86..8589ea2b3 100644
--- a/build.nix
+++ b/build.nix
@@ -1,4 +1,5 @@
-with import <nixpkgs> {};
+{ pkgs ? (import <nixpkgs> {}) }:
+with pkgs;
 rec {
     badvpnFunc = import ./badvpn.nix;
     badvpn = pkgs.callPackage badvpnFunc {};