Attempting to use this results in gzipped files downloading

[JaTochNietDan]

So when using this it constantly results in my browser downloading a gzipped file. I also get a panic from Martini saying the following:

[martini] PANIC: interface conversion: *martini.responseWriter is not martini.ResponseWriter: missing method Before

My code is as follows:

m := martini.Classic()
m.Use(gzip.All())
m.Use(render.Renderer())

m.Get("/", func() string {
    return "Test"
})