Docker Remote API does not separate stderr and stdout

I am using the Docker Remote API through a node wrapper in order to listen to the log stream.
I am using Docker for Windows version 1.12.0-rc3-beta18 (build 5226) ec40b14.

The request that gets sent is the following

GET /containers/d5053e3a9bd4/logs?follow=1&stdout=1&stderr=0&timestamps=1&since=1467905054

The full code is available here.

I can listen to the stream, however both stdout and stderr are sent to my stream. I would expect only stdout and not stderr.

How can I listen to only stdout?