ServiceStack EndpointHostConfig & WebHost does not exist? C# MVC

Following a tutorial of using ServiceStack, I'm trying to compile the following code:

public class AppHost : AppHostBase
{
    public AppHost() : base("Protein Tracker Web Services", typeof(HelloService).Assembly) { }

    public override void Configure(Funq.Container container)
    {
        SetConfig(new EndpointHostConfig { ServiceStackHandlerFactoryPath = "api" });
    }
}

This gives me the following error:

The type or namespace name 'EndpointHostConfig' could not be found (are you missing a using directive or an assembly reference?)

I tried to add the suggested:

using ServiceStack.WebHost.Endpoints;

Gives me the following error:

The type or namespace name 'WebHost' does not exist in the namespace 'ServiceStack' (are you missing an assembly reference?)