diff --git a/mv/5pkgs/default.nix b/mv/5pkgs/default.nix
index a852c2424..0c72c450e 100644
--- a/mv/5pkgs/default.nix
+++ b/mv/5pkgs/default.nix
@@ -12,7 +12,11 @@
         --disk-cache-size=50000000 \
         "%@"
   '';
-  ff = pkgs.callPackage ./ff {};
+  ff = pkgs.writeScriptBin "ff" ''
+    #! /bin/sh
+    set -efu
+    exec ${pkgs.firefoxWrapper}/bin/firefox $(printf " %q" "$@")
+  '';
   xmonad-tv =
     let src = pkgs.writeNixFromCabal "xmonad-tv.nix" ./xmonad-tv; in
     pkgs.haskellPackages.callPackage src {};
diff --git a/mv/5pkgs/ff/default.nix b/mv/5pkgs/ff/default.nix
deleted file mode 100644
index 2db404030..000000000
--- a/mv/5pkgs/ff/default.nix
+++ /dev/null
@@ -1,8 +0,0 @@
-{ pkgs, ... }:
-
-pkgs.writeScriptBin "ff" ''
- #! ${pkgs.bash}/bin/bash
- exec sudo -u ff -i <<EOF
- exec ${pkgs.firefoxWrapper}/bin/firefox $(printf " %q" "$@")
- EOF
-''