diff --git a/hosts/default.nix b/hosts/default.nix
index a8996a5..1a2c17a 100644
--- a/hosts/default.nix
+++ b/hosts/default.nix
@@ -56,7 +56,7 @@ in {
     hostname = "hermit";
   };
   tower = mkSystem {
-    system = "aarch_64-linux";
+    system = "aarch64-linux";
     hostname = "tower";
   };
 }
diff --git a/modules/system/nix/nixpkgs.nix b/modules/system/nix/nixpkgs.nix
index 97aee62..f240b96 100644
--- a/modules/system/nix/nixpkgs.nix
+++ b/modules/system/nix/nixpkgs.nix
@@ -6,7 +6,6 @@
   nixpkgs = {
     # Configuration reference:
     # <https://nixos.org/manual/nixpkgs/unstable/#chap-packageconfig>
-    hostPlatform = "x86_64-linux";
     config = {
       # Disallow broken packages to be built.       allowBroken = false;
       allowUnsupportedSystem = true;