diff --git a/default.nix b/default.nix
index 5614d0e..2acef1a 100644
--- a/default.nix
+++ b/default.nix
@@ -17,7 +17,7 @@ let
     };
     brownpaper = sequoia-openpgp; # requires gmp as well
   };
-  client = pkgs.writeShellScript "brownpaper" ''
+  client = pkgs.writeShellScriptBin "brownpaper" ''
     PATH=$PATH:${pkgs.gnupg}/bin/:${pkgs.curl}/bin/ ${./bp.sh} $@
   '';
 in