AndroidAsync Multipart POST request body doesn't contain submitted file

Question

I have a simple server in android that I'm trying to access from my PC. I can't handle POST requests with multipart data. The form data in the request body is always null

server.get("/status", new HttpServerRequestCallback() {
    @Override
    public void onRequest(AsyncHttpServerRequest request, AsyncHttpServerResponse response) {
        Log.d(TAG, "GET /status");
        response.send("Ok");
    }
});

server.post("/scan", new HttpServerRequestCallback() {
    @Override
    public void onRequest(AsyncHttpServerRequest request, AsyncHttpServerResponse response) {
         Log.d(TAG, "POST /scan");
         if (request.getBody() instanceof MultipartFormDataBody) {
             MultipartFormDataBody body = (MultipartFormDataBody) request.getBody();
         }
         response.send("Scanned");
     }
});

I placed a breakpoint inside post request handler and the formData of the request body is always null. I've been unable to access the file submitted in this POST request. I made my request using curl with the command below

curl -F 'filename=@/Users/l4rry/test/names.txt' http://192.168.1.178:8080/scan

I'm I doing something wrong? How can I get multipart POST to work?