diff --git a/flake.nix b/flake.nix
index a89ff2a..c20f4e5 100644
--- a/flake.nix
+++ b/flake.nix
@@ -34,6 +34,7 @@
           ./modules/letsencrypt.nix
           ./modules/fail2ban.nix
           ./modules/email.nix
+          ./modules/mastodon.nix
           agenix.nixosModules.default
           nixos-mailserver.nixosModules.default
           nixos-matrix-modules.nixosModules.default
diff --git a/modules/mastodon.nix b/modules/mastodon.nix
new file mode 100644
index 0000000..7035e14
--- /dev/null
+++ b/modules/mastodon.nix
@@ -0,0 +1,17 @@
+{ config, ... } :
+let
+  root_host = "grimmauld.de";
+  mastodon_host = "mastodon.${root_host}";
+in {
+  security.acme.certs."${root_host}".extraDomainNames = [ mastodon_host ];
+  services.mastodon = {
+    enable = true;
+    localDomain = mastodon_host;
+    streamingProcesses = 7;
+    configureNginx = true;
+    smtp = {
+      fromAddress = "noreply@${root_host}";
+    };
+    extraConfig.SINGLE_USER_MODE = "true";
+  };
+}