wp_list_authors including custom post types

Question

I am using wp_list_authors function to list all the users in my blog, however it doesn't display the users who wrote custom post types. it only displays the users who wrote regular posts. Is there a way of displaying all the users who wrote posts and also including the users who wrote custom post types in the same list?

I was looking for such answer and could not find it anywhere on the web. any help will be appreciated

Thanks, Gil