Wordpress Nginx, WordPress, and Trailing Slash 301 Redirects

I've recently noted that Nginx is returning the same WordPress pages for multiple URLs, with and without the trailing slash. For example:

---

www.example.com/contact

and

www.example.com/contact/

...will both return the same page, but they won't redirect to one form or the other. Even though using rel="canonical" can mitigate this issue, it can be an SEO concern and can cause mis-reporting in Google Analytics, because the address to the same page can have different URLs.

Please correct me if I'm wrong, but I believe the Centminmod Nginx configuration, by default, will provide a 301 redirect to form of the URL with the trailing slash. So...

www.example.com/contact

=> 301 redirect to... =>

www.example.com/contact/

That is how it works with actual directories, but if WordPress is handling the URL re-writes, it's not working as expected. I thought I had solved the issue with the following rule in my site's vhost.conf:

Code:

location ~ /^([^.\?]*[^/])$ {
        try_files       $uri @addslash;
}
location @addslash {
        return 301 $uri/;
}

This was tested and working for me, but it stopped and I don't know exactly when or why.

Is there another way I should be doing this? Perhaps this is something that Centminmod's WordPress Nginx re-write rules can address in the future?