diff --git a/es6-promise/es6-promise-commonjs-tests.ts b/es6-promise/es6-promise-commonjs-tests.ts
index b5a2fcbe49..308a042ec6 100644
--- a/es6-promise/es6-promise-commonjs-tests.ts
+++ b/es6-promise/es6-promise-commonjs-tests.ts
@@ -1,6 +1,7 @@
 /// <reference path="es6-promise.d.ts" />
 
 import rsvp = require('es6-promise');
+rsvp.polyfill(); // Test for polyfill method existence
 var Promise = rsvp.Promise;
 
 var promiseString: Promise<string>,
diff --git a/es6-promise/es6-promise.d.ts b/es6-promise/es6-promise.d.ts
index 001330fd24..b5d0241374 100644
--- a/es6-promise/es6-promise.d.ts
+++ b/es6-promise/es6-promise.d.ts
@@ -79,6 +79,7 @@ declare module 'es6-promise' {
 	var foo: typeof Promise; // Temp variable to reference Promise in local context
 	namespace rsvp {
 		export var Promise: typeof foo;
+		export function polyfill(): void;
 	}
 	export = rsvp;
 }