diff --git a/modules/nixos/builder/default.nix b/modules/nixos/builder/default.nix
index 66e2f36..fa45bb5 100644
--- a/modules/nixos/builder/default.nix
+++ b/modules/nixos/builder/default.nix
@@ -31,12 +31,12 @@ in
   config = lib.mkIf cfg.enable {
     nix.buildMachines = [
       {
-        hostName = "192.168.3.118";
-        system = "x86_64-linux";
+        hostName = "builder.julian-mutter.de";
         protocol = "ssh";
-        # if the builder supports building for multiple architectures,
-        # replace the previous line by, e.g.
-        # systems = ["x86_64-linux" "aarch64-linux"];
+        systems = [
+          "x86_64-linux"
+          "aarch64-linux"
+        ];
         maxJobs = 4;
         speedFactor = 3;
         supportedFeatures = [
@@ -50,6 +50,6 @@ in
     ];
     nix.distributedBuilds = true;
     # optional, useful when the builder has a faster internet connection than yours
-    nix.extraOptions = "  builders-use-substitutes = true\n";
+    # nix.extraOptions = "  builders-use-substitutes = true\n";
   };
 }