diff --git a/realm/index.d.ts b/realm/index.d.ts
index 3c3a438621..974f2a4ed1 100644
--- a/realm/index.d.ts
+++ b/realm/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/realm/realm-js
 // Definitions by: Akim <https://github.com/Akim95>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.1
 
 declare namespace Realm {
     /**