diff --git a/nixos/modules/system/boot/loader/grub/grub.nix b/nixos/modules/system/boot/loader/grub/grub.nix
index ed2249a4ba7..0cfef7df197 100644
--- a/nixos/modules/system/boot/loader/grub/grub.nix
+++ b/nixos/modules/system/boot/loader/grub/grub.nix
@@ -29,7 +29,7 @@ let
   grubConfig = pkgs.writeText "grub-config.xml" (builtins.toXML
     { splashImage = f config.boot.loader.grub.splashImage;
       grub = f grub;
-      grubTarget = f grub.grubTarget;
+      grubTarget = f (grub.grubTarget or "");
       shell = "${pkgs.stdenv.shell}";
       fullVersion = (builtins.parseDrvName realGrub.name).version;
       grubEfi = f grubEfi;