diff --git a/router.go b/router.go
index 0b29fab..80f8e0f 100644
--- a/router.go
+++ b/router.go
@@ -24,10 +24,17 @@ func NewRouter(mux *http.ServeMux, requiredRoutes []string) (ro *Router) {
 		ServeMux: mux,
 		routes:   make(map[Route]*server),
 	}
+	ro.AddRequiredRoutes(requiredRoutes)
+	return
+}
+
+func (ro *Router) AddRequiredRoutes(requiredRoutes []string) {
+	if requiredRoutes == nil {
+		return
+	}
 	for _, pattern := range requiredRoutes {
 		ro.routes[Route{pattern: pattern, required: true}] = &server{}
 	}
-	return
 }
 
 func (ro *Router) Register(pattern string, server *server) (err error) {