jQuery .post() not executing

I have the following AJAX call through jQuery:

// var upload = some JSON data
$.post('/videos/upload', upload);

And this express.js API part to handle the request:

app.post('/videos/upload', function(request, response) {
    console.log('Request received')
}

However, when .post() is called, it does not seem to be executing. The request is nowhere to be seen in Firebug's Net logger, and the node.js console doesn't log anything, either.

When I type the request directly into the Firebug console, it executes just fine.

Using $.ajax() does not work, either.

Thanks in advance.