Permalinks – .html extension and trailing slashes

Heya,

So I want my categories to end with the trailing slash “mysite.com/category/” and my actual posts end with .html so “mysite.com/category/post.html”

I can get the .html but then the categories for some reason don’t have trailing slashes.

Here’s what my permalink code looks like:
/%category%/%postname%.html

Any ideas?