diff --git a/promise.prototype.finally/promise.prototype.finally.d.ts b/promise.prototype.finally/promise.prototype.finally.d.ts
new file mode 100644
index 0000000000..d8c94069c7
--- /dev/null
+++ b/promise.prototype.finally/promise.prototype.finally.d.ts
@@ -0,0 +1,5 @@
+declare module 'es6-promise/dist/es6-promise' {
+    export interface Promise <R> {
+      finally?<U>(onFinally?: () => U | Promise<U>): Promise<U>;
+    }
+}