Rewrite Middleware in Route

[phhoef]

I would like to rewrite the URL for a specific route.
I tried it like this, but it is not working

	mux.Route("/endpoint", func(r chi.Router) {
              	r.Use(middleware.RewriteRoute)
		r.Route("/{source}", func(r chi.Router) {
			r.Get("/handler", myHandler)
		})
	})

Though, when moving the middleware to the outer scope it is working.

	mux.Use(middleware.RewriteRoute)
	mux.Route("/endpoint", func(r chi.Router) {
		r.Route("/{source}", func(r chi.Router) {
			r.Get("/handler", myHandler)
		})
	})

Can someone please explain what's wrong with my idea?