diff --git a/pkgs/build-support/vm/windows/default.nix b/pkgs/build-support/vm/windows/default.nix
index 758120ed4f2..f9b44d450d9 100644
--- a/pkgs/build-support/vm/windows/default.nix
+++ b/pkgs/build-support/vm/windows/default.nix
@@ -28,7 +28,7 @@ in {
     bootstrap = bootstrapper attrs.windowsImage;
   in {
     requiredSystemFeatures = [ "kvm" ];
-    buildur = "${pkgs.stdenv.shell}";
+    builder = "${pkgs.stdenv.shell}";
     args = ["-e" (bootstrap.resumeAndRun builder)];
     windowsImage = bootstrap.suspendedVM;
     origArgs = attrs.args;