RouteDataArgs Type Error for nested RouteData

// Root
export function routeData(args: RouteDataArgs) {
  return () => 'foo'
}

// Child
export function routeData(args: RouteDataArgs<typeof RootRouteData>) {
  return args.data() ? args.data() : () => 'bar'
}

// Grandchild
export function routeData(args: RouteDataArgs<typeof ChildRouteData>) {
  return args.data() // <= TypeError. An Argument for "args" was not provided.
}