diff --git a/react-json-pretty/index.d.ts b/react-json-pretty/index.d.ts
index 5ca8bbf13b..bf165faaf5 100644
--- a/react-json-pretty/index.d.ts
+++ b/react-json-pretty/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/chenckang/react-json-pretty
 // Definitions by: Karol Janyst <https://github.com/LKay>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.1
 
 import { ComponentClass, HTMLProps } from "react";