diff --git a/modules/graphical/firefox/default.nix b/modules/graphical/firefox/default.nix
index 6e717ca3..cefe4c86 100644
--- a/modules/graphical/firefox/default.nix
+++ b/modules/graphical/firefox/default.nix
@@ -3,12 +3,12 @@
 let
   ff2mpv-host = pkgs.stdenv.mkDerivation rec {
     pname = "ff2mpv";
-    version = "3.9.1";
+    version = "4.0.0";
     src = pkgs.fetchFromGitHub {
       owner = "woodruffw";
       repo = "ff2mpv";
       rev = "v${version}";
-      sha256 = "j2VjHRhadLaftWRv0zrzOyg/pizD/kvr9RBb2ozjKDw=";
+      sha256 = "sxUp/JlmnYW2sPDpIO2/q40cVJBVDveJvbQMT70yjP4=";
     };
     buildInputs = [ pkgs.python3 ];
     buildPhase = ''
@@ -60,17 +60,6 @@ let
       platforms = platforms.all;
     };
   };
-  ff2mpv = pkgs.nur.repos.rycee.firefox-addons.buildFirefoxXpiAddon rec {
-    pname = "ff2mpv";
-    version = "3.9.1";
-    addonId = "ff2mpv@yossarian.net";
-    url = "https://addons.mozilla.org/firefox/downloads/file/3874208/ff2mpv-${version}-fx.xpi";
-    sha256 = "AJO9h2jv/VmqlfShu8q7VqJ7N+bGBtippaODZeCCM6I=";
-    meta = with lib; {
-      license = licenses.mit;
-      platforms = platforms.all;
-    };
-  };
   zotero-connector = pkgs.nur.repos.rycee.firefox-addons.buildFirefoxXpiAddon rec {
     pname = "zotero-connector";
     version = "5.0.92";