I'm unable to get correct Content-Type as a response from spray-json marshaling (in akka-http).

I'm using similar code to this in my routing:

complete {
    val u: User = service.getUser(...)
    Jsonapi.asRootObject(u)
}

I have appropriate JsonapiRootObjectWriter[User] in scope and getting JSON output as expected, only issue I have is that Content-Type is application/json instead of application/vnd.api+json

I'm using latest scala-jsonapi and akka-http v 2.4.4