Make parent’s count include posts using wp_list_cats optioncount

I am using the hierarchical view with post counts showing for categories with wp_list_cats – One thing I’ve noticed is that if you click on ParentA, it will show you posts that have been categorized as ParentA as well as ChildA.1 and ChildA.2 – as I want it to. What it doesn’t do is in the post count next to ParentA – it only shows posts that are explicitly categorized as ParentA without including any posts that are only categorized as the children categories. Is it possible to make the ParentA count to include it’s children’s post counts?