diff --git a/flake.nix b/flake.nix
index ef285bb..fcbb5bb 100644
--- a/flake.nix
+++ b/flake.nix
@@ -43,7 +43,7 @@
   };
 
   outputs = { nixpkgs, flake-utils, lanzaboote, agenix, home-manager
-    , nixos-hardware, ... }@attrs:
+    , nixos-hardware, ... }@inputs:
 
     (flake-utils.lib.eachDefaultSystem (system:
       let pkgs = nixpkgs.legacyPackages.${system};
@@ -62,7 +62,7 @@
         # neodymium laptop
         nixosConfigurations.neodymium = nixpkgs.lib.nixosSystem {
           system = "x86_64-linux";
-          specialArgs = attrs;
+          specialArgs = inputs;
           modules = [
             ./hosts/neodymium
             home-manager.nixosModules.home-manager
diff --git a/hosts/neodymium/system/nix/default.nix b/hosts/neodymium/system/nix/default.nix
index ca85fc7..451c964 100644
--- a/hosts/neodymium/system/nix/default.nix
+++ b/hosts/neodymium/system/nix/default.nix
@@ -1,4 +1,4 @@
-{ lib, pkgs, ... }: {
+{ lib, pkgs, nixpkgs, ... }: {
   # restrict nix command to sudoers
   nix.settings.allowed-users = [ "@wheel" ];
 
@@ -25,6 +25,9 @@
     ];
   };
 
+  # pin nixpkgs registry
+  nix.registry.nixpkgs.flake = nixpkgs;
+
   # list of allowed unfree packages
   nixpkgs.config.allowUnfreePredicate = pkg:
     builtins.elem (lib.getName pkg) [