diff --git a/deploy.nix b/deploy.nix
index e8886c7..dcfa2a2 100644
--- a/deploy.nix
+++ b/deploy.nix
@@ -15,11 +15,12 @@ in {
 
     nodes = mkDeployNodes (name: machine: let
       nixosConfiguration = self.nixosConfigurations.${name};
+      machineArch = nixosConfiguration.config.facter.report.system;
     in {
       hostname = nixosConfiguration.config.networking.fqdn;
       profiles.system = {
-        remoteBuild = machine.arch != deployArch;
-        path = deploy-rs.lib.${machine.arch}.activate.nixos nixosConfiguration;
+        remoteBuild = machineArch != deployArch;
+        path = deploy-rs.lib.${machineArch}.activate.nixos nixosConfiguration;
       };
     });
   };
diff --git a/machines/atlas/default.nix b/machines/atlas/default.nix
index a0845e0..aae82bc 100644
--- a/machines/atlas/default.nix
+++ b/machines/atlas/default.nix
@@ -1,6 +1,5 @@
 {
   machines.atlas = {
-    arch = "x86_64-linux";
     kubernetesNodeLabels.storageType = "slow";
     facterReportPath = ./facter.json;
 
diff --git a/machines/default.nix b/machines/default.nix
index c32a0b4..5aab827 100644
--- a/machines/default.nix
+++ b/machines/default.nix
@@ -9,14 +9,6 @@ flake-utils.lib.eachDefaultSystem (system: let
 
   machineOpts = {config, ...}: {
     options = {
-      arch = lib.mkOption {
-        default = null;
-        type = with lib.types; nullOr str;
-        description = ''
-          CPU architecture of this machine.
-        '';
-      };
-
       facterReportPath = lib.mkOption {
         default = null;
         type = with lib.types; nullOr path;
diff --git a/machines/jefke/default.nix b/machines/jefke/default.nix
index f423c08..ffab64b 100644
--- a/machines/jefke/default.nix
+++ b/machines/jefke/default.nix
@@ -1,6 +1,5 @@
 {
   machines.jefke = {
-    arch = "x86_64-linux";
     kubernetesNodeLabels.storageType = "fast";
     facterReportPath = ./facter.json;
 
diff --git a/machines/lewis/default.nix b/machines/lewis/default.nix
index 5b6f580..2dcf470 100644
--- a/machines/lewis/default.nix
+++ b/machines/lewis/default.nix
@@ -1,6 +1,5 @@
 {
   machines.lewis = {
-    arch = "x86_64-linux";
     kubernetesNodeLabels = {
       storageType = "fast";
       hasMedia = "true";
diff --git a/machines/talos.nix b/machines/talos.nix
index 56ada95..cbcc0b1 100644
--- a/machines/talos.nix
+++ b/machines/talos.nix
@@ -1,7 +1,5 @@
 {
   machines.talos = {
-    arch = "x86_64-linux";
-
     nixosModule = {lib, ...}: {
       lab.storage.profile = "normal";
 
diff --git a/machines/warwick/default.nix b/machines/warwick/default.nix
index 0035e27..a9e740b 100644
--- a/machines/warwick/default.nix
+++ b/machines/warwick/default.nix
@@ -1,6 +1,5 @@
 {
   machines.warwick = {
-    arch = "aarch64-linux";
     facterReportPath = ./facter.json;
 
     nixosModule = {inputs, ...}: {
diff --git a/modules/default.nix b/modules/default.nix
index 99e0605..ef7de1c 100644
--- a/modules/default.nix
+++ b/modules/default.nix
@@ -29,7 +29,7 @@
       overlays = [
         (final: _prev: {
           unstable = import inputs.nixpkgs-unstable {
-            system = machine.arch;
+            system = config.nixpkgs.hostPlatform.system;
           };
         })
       ];
diff --git a/modules/k3s/default.nix b/modules/k3s/default.nix
index 9b00024..e193271 100644
--- a/modules/k3s/default.nix
+++ b/modules/k3s/default.nix
@@ -1,5 +1,4 @@
 {
-  self,
   inputs,
   pkgs,
   lib,