diff --git a/system/options.nix b/system/options.nix
index a50ab43929f..a403ca81c00 100644
--- a/system/options.nix
+++ b/system/options.nix
@@ -1973,7 +1973,7 @@ root        ALL=(ALL) SETENV: ALL
     };
 
     nix = mkOption {
-      default = pkgs: pkgs.nix;
+      default = pkgs: pkgs.nixUnstable;
       example = pkgs: pkgs.nixCustomFun /root/nix.tar.gz;
       description = "
         Use non-default Nix easily. Be careful, though, not to break everything.