diff --git a/hosts/lars/kronos/configuration.nix b/hosts/lars/kronos/configuration.nix
index 0189d05..c7d1182 100644
--- a/hosts/lars/kronos/configuration.nix
+++ b/hosts/lars/kronos/configuration.nix
@@ -15,6 +15,9 @@
 			    "DP-1,1920x1080@60,2560x0,1"
 			];
       };
+      firefox = {
+	  enable = true;
+      };
   };
 
   services.getty.autologinUser = "lars";
diff --git a/modules/gui/default.nix b/modules/gui/default.nix
index d4cd205..70631a4 100644
--- a/modules/gui/default.nix
+++ b/modules/gui/default.nix
@@ -11,5 +11,6 @@ _: {
         ./foot.nix
 #        ./vivado.nix
         ./WM
+	./firefox.nix
     ];
 }
diff --git a/modules/gui/firefox.nix b/modules/gui/firefox.nix
new file mode 100644
index 0000000..79626a3
--- /dev/null
+++ b/modules/gui/firefox.nix
@@ -0,0 +1,30 @@
+{ config, lib, inputs, pkgs, ... }:
+with lib; let
+  username = config.modules.other.system.username;
+  cfg = config.modules.firefox;
+in {
+    options.modules.firefox = {
+      enable = mkEnableOption "firefox";
+      extensions = mkOption {
+        description = "firefox extensions (format like https://discourse.nixos.org/t/declare-firefox-extensions-and-settings/36265)";
+	type = types.attrs;
+	default = {};
+      };
+    };
+
+  config = mkIf cfg.enable {
+    home-manager.users.${username} = {
+      programs.firefox = (lib.mkMerge [{
+        enable = true;
+	policies = {
+	  ExtensionSettings = {
+	    "uBlock0@raymondhill.net" = {
+              install_url = "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi";
+              installation_mode = "force_installed";
+            };
+	  };
+	};
+      } cfg.extensions]);
+    };
+  };
+}