diff --git a/user/firefox.nix b/user/firefox.nix
index 48c4fc9..063cd26 100644
--- a/user/firefox.nix
+++ b/user/firefox.nix
@@ -61,11 +61,6 @@ in
             hash = "sha256-ApCc+MNmW9Wd/5seV6npePQVEaszT/rhD9EB7HGiUb8=";
           })
 
-          (pkgs.fetchFirefoxAddon {
-            name = "mastodon_simplified_federation";
-            url = "https://addons.mozilla.org/firefox/downloads/file/4215691/mastodon_simplified_federation-2.2.xpi";
-            hash = "sha256-4iU25chpjsdsMTPaa0yQOTWc9V9q1qFz6YV0lYtNjLA=";
-          })
           (pkgs.fetchFirefoxAddon {
             name = "substitoot";
             url = "https://addons.mozilla.org/firefox/downloads/file/4236602/substitoot-0.7.2.0.xpi";