How do I make the category sidebar widget (stock) display the total # of posts including those in subcategories?

This isn’t THE answer, but it’s one answer.

Quick fix: Have my clients check two boxes whenever they use a sub-category. (sub-category box + parent category). This will ensure the post-count is correct.

Events [x]
  Meals and Mission [x]

Would love a fix that didn’t depend on clients checking both boxes all the time.