diff --git a/types/activex-wia/index.d.ts b/types/activex-wia/index.d.ts
index ff7253c335..51ef3c59f7 100644
--- a/types/activex-wia/index.d.ts
+++ b/types/activex-wia/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://msdn.microsoft.com/en-us/library/windows/desktop/ms630368(v=vs.85).aspx
 // Definitions by: Zev Spitz <https://github.com/zspitz>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// Typescript Version: 2.4
 
 declare namespace WIA {
     /** String versions of globally unique identifiers (GUIDs) that identify common Device and Item commands. */