Guzzle & Homestead: CURL Connection reset by peer error

When I curl a URL from my local machine, everything is fine. When I curl the URL while SSH'd in my Vagrant Homestead box, everything is fine.

But when I send the same request via Guzzle in my app, I get back:

cURL error 56: Recv failure: Connection reset by peer (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)

Nothing has changed with my app except updating my Vagrant box. Has anyone ever seen this? Any idea how I can even debug it? I do believe it has something to do with Guzzle but Google has not been kind to me on this one.