Views header being cached

I'm using a view to replace the default taxonomy/term pages. In the header of the view I'm trying to print the term description. The problem is it's caching the description of the term that was first loaded so all of the term pages show the same description. If I edit the view and load another term page it caches that one.

What do I need to do to prevent it caching the header?

Here's the code I'm using in the header

$view = views_get_current_view();
$term = taxonomy_get_term($view->args[0]);
print check_markup($term->description, 2);