Category ID Issues with 2.1.2

Hi,

I’m currently hiding a category from displaying on my index page with the following:

<?php
   if (is_home()) {
      query_posts("cat=-16");
   }
?>

What must this change to for this to work following my upgrade to 2.1.2? I’ve tried the Codex, but I’m having difficulties fully understanding what has changed to the category ID tag.

Thanks!