diff --git a/modules/virtualisation/qemu-vm.nix b/modules/virtualisation/qemu-vm.nix
index add88753f00..098c2944c1b 100644
--- a/modules/virtualisation/qemu-vm.nix
+++ b/modules/virtualisation/qemu-vm.nix
@@ -274,6 +274,10 @@ in
 
   boot.initrd.postMountCommands =
     ''
+      # Mark this as a NixOS machinex.
+      mkdir -p $targetRoot/etc
+      echo -n > $targetRoot/etc/NIXOS
+    
       # Fix the permissions on /tmp.
       chmod 1777 $targetRoot/tmp