diff --git a/hosts/toaster/default.nix b/hosts/toaster/default.nix
index 1a3216a..7e78114 100644
--- a/hosts/toaster/default.nix
+++ b/hosts/toaster/default.nix
@@ -46,6 +46,11 @@
     supportedLocales = [ "all" ];
   };
 
+  # support ddc brigtness control
+  hardware.i2c.enable = true;
+  boot.kernelModules = [ "i2c-dev" ];
+  environment.systemPackages = [ pkgs.ddcutil ];
+
   users.users."0xa" = {
     extraGroups = [
       "wheel"
@@ -55,6 +60,7 @@
       "bluetooth"
       "libvirtd"
       "qemu-libvirtd"
+      "i2c"
     ];
     group = "users";
     home = "/home/0xa";