diff --git a/types/await-timeout/index.d.ts b/types/await-timeout/index.d.ts
index de6aa1a82b..ce202c6024 100644
--- a/types/await-timeout/index.d.ts
+++ b/types/await-timeout/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/vitalets/await-timeout
 // Definitions by: Sean Zhu <https://github.com/szhu>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.1
 
 export default Timeout;