Play tries to chunk response when not allowed by request

I'm trying to return an InputStream from a URL and it is failing with the error:

    The response to this request is chunked and hence requires HTTP 1.1 to be sent, but this is a HTTP 1.0 request.

The code I'm using is:

    try (InputStream is = new URL(url).openStream()) {
      return ok(is);
    }

It's odd that Play knows it cannot chunk the response and yet tries to anyway.