WordPress not adding a trailing slash anymore?

I noticed that with the latest WP version I now can access my posts via:

domain.com/post-title

and

domain.com/post-title/

Google used to treat those are different pages, and I believe it still might do so, so ideally you want to have one version redirecting to the other.

WordPress used to do this by default didn’t it? How come it’s not doing anymore?

Update: Never mind. I noticed this behavior is caused by the W3 Total Cache Plugin.