diff --git a/pkgs/npiperelay/default.nix b/pkgs/npiperelay/default.nix
index 1acfbc7..8cb7a68 100644
--- a/pkgs/npiperelay/default.nix
+++ b/pkgs/npiperelay/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl }:
+{ lib, stdenv, fetchurl, gzip, gnutar }:
 
 let
   version = "1.6.3";
@@ -41,7 +41,7 @@ in stdenv.mkDerivation rec {
     # it fails to detect ConBee2.
     homepage =
       "https://github.com/rupor-github/wsl-ssh-agent";
-    license = licenses.free;
+    license = licenses.unfree;
     platforms = [ "x86_64-linux" ];
     maintainers = with maintainers; [ sstent ];
   };