diff --git a/README.md b/README.md
index 57bc26285..f8a103dd1 100755
--- a/README.md
+++ b/README.md
@@ -222,6 +222,7 @@ List of Definitions
 * [Parallel.js](https://github.com/adambom/parallel.js) (by [Josh Baldwin](https://github.com/jbaldwin))
 * [Parsimmon](https://github.com/jayferd/parsimmon) (by [Bart van der Schoor](https://github.com/Bartvds))
 * [PDF.js](https://github.com/mozilla/pdf.js) (by [Josh Baldwin](https://github.com/jbaldwin))
+* [PEG.js](http://pegjs.majda.cz/) (by [vvakame](https://github.com/vvakame))
 * [Persona](http://www.mozilla.org/en-US/persona) (by [James Frasca](https://github.com/Nycto))
 * [PhantomJS](http://phantomjs.org) (by [Jed Hunsaker](https://github.com/jedhunsaker))
 * [PhoneGap](http://phonegap.com) (by [Boris Yankov](https://github.com/borisyankov))
diff --git a/pegjs/pegjs-tests.ts b/pegjs/pegjs-tests.ts
new file mode 100644
index 000000000..90ebe2da1
--- /dev/null
+++ b/pegjs/pegjs-tests.ts
@@ -0,0 +1,5 @@
+/// <reference path="./pegjs.d.ts" />
+
+var input: string;
+var result = PEG.parse(input);
+console.log(result);
diff --git a/pegjs/pegjs.d.ts b/pegjs/pegjs.d.ts
new file mode 100644
index 000000000..c42b9aae5
--- /dev/null
+++ b/pegjs/pegjs.d.ts
@@ -0,0 +1,19 @@
+// Type definitions for PEG.js
+// Project: http://pegjs.majda.cz/
+// Definitions by: vvakame <https://github.com/vvakame>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+declare module PEG {
+	function parse(input:string):any;
+
+	class SyntaxError {
+		line:number;
+		column:number;
+		offset:number;
+
+		expected:any[];
+		found:any;
+		name:string;
+		message:string;
+	}
+}