diff --git a/lib/nixos.nix b/lib/nixos.nix
index 52b2eeea..b58a6b34 100644
--- a/lib/nixos.nix
+++ b/lib/nixos.nix
@@ -1,5 +1,5 @@
 # All of the functions suitable only for NixOS.
-{ pkgs, lib }:
+{ pkgs, config, lib }:
 
 rec {
   # This is only used for home-manager users without a NixOS user counterpart.
@@ -30,4 +30,14 @@ rec {
         settings
       ];
     });
+
+  # Checks if the NixOS configuration is part of the nixos-generator build.
+  # Typically, we just check if there's a certain attribute that is imported
+  # from it.
+  hasNixosFormat =
+    pkgs.lib.hasAttrByPath [ "formatAttr" ] config;
+
+  # Checks if the NixOS config is being built for a particular format.
+  isFormat = format:
+    hasNixosFormat && config.formatAttr == format;
 }
diff --git a/modules/nixos/_private/extra-arguments.nix b/modules/nixos/_private/extra-arguments.nix
index b9f4e072..62230e36 100644
--- a/modules/nixos/_private/extra-arguments.nix
+++ b/modules/nixos/_private/extra-arguments.nix
@@ -1,6 +1,6 @@
 # All of the extra module arguments to be passed as part of the holistic NixOS
 # system.
-{ options, lib, pkgs, ... }:
+{ config, options, lib, pkgs, ... }:
 
 let
   foodogsquaredLib = import ../../../lib { inherit pkgs; };
@@ -8,7 +8,7 @@ in
 {
   _module.args.foodogsquaredLib =
     foodogsquaredLib.extend (final: prev:
-      import ../../../lib/nixos.nix { inherit pkgs; lib = prev; }
+      import ../../../lib/nixos.nix { inherit pkgs config; lib = prev; }
       // lib.optionalAttrs (options?sops) {
         sops-nix = import ../../../lib/sops.nix { inherit pkgs; lib = prev; };
       });