diff --git a/types/autoprefixer/index.d.ts b/types/autoprefixer/index.d.ts
index 4650f1d407..faf11371db 100644
--- a/types/autoprefixer/index.d.ts
+++ b/types/autoprefixer/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/postcss/autoprefixer
 // Definitions by:  Armando Meziat <https://github.com/odnamrataizem>, murt <https://github.com/murt>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.2
 
 import { Plugin } from "postcss";