Use the same version of nixpkgs for nix-shell

configuration.nix

@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, inputs, ... }:
 
 with pkgs;
 
@@ -129,6 +129,10 @@ in {
     options mac80211 beacon_loss_count=1000 probe_wait_ms=75
   '';
 
+  # Use same version of nixpkgs for nix-shell
+  nix.nixPath = let path = toString ./.;
+  in [ "nixpkgs=${inputs.nixpkgs}" "nixos-config=${path}/configuration.nix" ];
+
   # Import other configuration modules
   imports = [
     ./modules/hardware-configuration.nix