diff --git a/ms/ms-tests.ts b/ms/ms-tests.ts
new file mode 100644
index 0000000000..75312e9277
--- /dev/null
+++ b/ms/ms-tests.ts
@@ -0,0 +1,14 @@
+/// <reference path="./ms.d.ts"/>
+
+import ms = require('ms');
+
+ms('2 days')  // 172800000 
+ms('1d')      // 86400000 
+
+ms(60000)             // "1m" 
+ms(2 * 60000)         // "2m" 
+ms(ms('10 hours'))    // "10h" 
+
+ms(60000, { long: true })             // "1 minute" 
+ms(2 * 60000, { long: true })         // "2 minutes" 
+ms(ms('10 hours'), { long: true })    // "10 hours" 
\ No newline at end of file
diff --git a/ms/ms.d.ts b/ms/ms.d.ts
new file mode 100644
index 0000000000..5a7c67add2
--- /dev/null
+++ b/ms/ms.d.ts
@@ -0,0 +1,30 @@
+// Type definitions for ms v0.7.1
+// Project: https://github.com/guille/ms.js
+// Definitions by: Zhiyuan Wang <https://github.com/danny8002/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+declare module 'ms' {
+
+    interface IMSOptions {
+        long: boolean
+    }
+
+    /**
+    * Short/Long format for `value`.
+    *
+    * @param {Number} value
+    * @param {{long: boolean}} options
+    * @return {String}
+    */
+    function ms(value: number, options?: IMSOptions): string;
+
+    /**
+    * Parse the given `value` and return milliseconds.
+    *
+    * @param {String} value
+    * @return {Number}
+    */
+    function ms(value: string): number;
+
+    export = ms;
+}
\ No newline at end of file