diff --git a/types/gzip-js/index.d.ts b/types/gzip-js/index.d.ts
index 2807e698a8..0a5c0000ea 100644
--- a/types/gzip-js/index.d.ts
+++ b/types/gzip-js/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/beatgammit/gzip-js
 // Definitions by: rhysd <https://github.com/rhysd>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.1
 
 /// <reference types="node" />