Shouldn't rx.stream set the response encoding to UTF-8?

The Server Sent Events spec says:

Event streams are always decoded as UTF-8.

But I get an non UTF-8 encoded stream/response (with Apache Tomcat 8.0). I have to explicitly call response.setCharacterEncoding("UTF-8") in my Controller Action before returning rx.stream.

In my case Apache uses his default encoding of ISO8859-1.