diff --git a/nixos/configuration.nix b/nixos/configuration.nix
index 8b9c164..8174231 100644
--- a/nixos/configuration.nix
+++ b/nixos/configuration.nix
@@ -115,8 +115,10 @@ in {
   # scanners
   hardware.sane = 
     { enable = true;
-      extraBackends = [ pkgs.hplip ];
+      extraBackends = [ pkgs.hplipWithPlugin ];
     };
+  nixpkgs.config.allowUnfreePredicate = (pkg:
+    pkg.name == pkgs.hplipWithPlugin.name );
 
   # Enable sound.
   sound.enable = true;