diff --git a/types/node/index.d.ts b/types/node/index.d.ts
index 67f275c7b6..bcb24150f8 100644
--- a/types/node/index.d.ts
+++ b/types/node/index.d.ts
@@ -1,6 +1,9 @@
 // Type definitions for Node.js v7.x
 // Project: http://nodejs.org/
-// Definitions by: Microsoft TypeScript <http://typescriptlang.org>, DefinitelyTyped <https://github.com/DefinitelyTyped/DefinitelyTyped>, Parambir Singh <https://github.com/parambirs>
+// Definitions by: Microsoft TypeScript <http://typescriptlang.org>
+//                 DefinitelyTyped <https://github.com/DefinitelyTyped/DefinitelyTyped>
+//                 Parambir Singh <https://github.com/parambirs>
+//                 Roberto Desideri <https://github.com/RobDesideri>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 /************************************************
@@ -2569,8 +2572,9 @@ declare module "fs" {
      * @returns Returns the created folder path.
      */
     export function mkdtempSync(prefix: string): string;
-    export function readdir(path: string | Buffer, callback?: (err: NodeJS.ErrnoException, files: string[]) => void): void;
-    export function readdirSync(path: string | Buffer): string[];
+    export function readdir(path: string | Buffer, callback: (err: NodeJS.ErrnoException, files: string[]) => void): void;
+    export function readdir(path: string | Buffer, options: string | Object, callback: (err: NodeJS.ErrnoException, files: string[]) => void): void;
+    export function readdirSync(path: string | Buffer, options?: string | Object): string[];
     export function close(fd: number, callback?: (err?: NodeJS.ErrnoException) => void): void;
     export function closeSync(fd: number): void;
     export function open(path: string | Buffer, flags: string | number, callback: (err: NodeJS.ErrnoException, fd: number) => void): void;