diff --git a/types/microrouter/index.d.ts b/types/microrouter/index.d.ts
index 934affd630..81643c9c42 100644
--- a/types/microrouter/index.d.ts
+++ b/types/microrouter/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for microrouter 2.2
+// Type definitions for microrouter 3.1.3
 // Project: https://github.com/pedronauck/micro-router#readme
 // Definitions by: Mathieu Dutour <https://github.com/mathieudutour>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
@@ -21,6 +21,7 @@ export type AugmentedRequestHandler = (
 export type RouteHandler = (path: string, handler: AugmentedRequestHandler) => RequestHandler;
 
 export function router(...routes: RequestHandler[]): RequestHandler;
+export function withNamespace(namespace: string): (...routes: RequestHandler[]) => RequestHandler;
 
 export const get: RouteHandler;
 export const post: RouteHandler;