diff --git a/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix b/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix
index 7f7ab9ede47e..f4a2884964f5 100644
--- a/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix
+++ b/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix
@@ -1,10 +1,6 @@
 # This module contains the basic configuration for building a graphical NixOS
 # installation CD.
-
 { lib, pkgs, ... }:
-
-with lib;
-
 {
   imports = [ ./installation-cd-base.nix ];
 
@@ -26,7 +22,7 @@ with lib;
 
   # Provide networkmanager for easy wireless configuration.
   networking.networkmanager.enable = true;
-  networking.wireless.enable = mkImageMediaOverride false;
+  networking.wireless.enable = lib.mkImageMediaOverride false;
 
   # KDE complains if power management is disabled (to be precise, if
   # there is no power management backend such as upower).