Do I NEED middleman-syntax for highlighting with Kramdown?

I’m a slightly confused Jekyll migrant.

I’d like to use Kramdown because that’s what I’ve been using. I see Kramdown is the default engine, and Kramdown supports code block formatting on its own, if I understand the website correctly (and in my default Middleman installation, I see Rouge in my Gemfile.lock).

However, I have only gotten highlighting to work after installing middleman-syntax and setting activate :syntax (no other options changed or added).

This is fine - I can progress with my CSS styling now - but I’d like to know if I’ve done something wrong. With an out-of-the-box Middleman site, is syntax highlighting possible via Kramdown alone, or is the middleman-syntax gem a minimum requirement to get it working (the GitHub page makes it sound like it only adds a helper method which I’m not interested in using)?

Sorry for the redundant topic; I know there are tons of “syntax highlighting not working” threads, but I haven’t found an answer to my questions in any one of them.