diff --git a/types/node/index.d.ts b/types/node/index.d.ts
index 09f8498359..f6b25c85c5 100644
--- a/types/node/index.d.ts
+++ b/types/node/index.d.ts
@@ -6222,6 +6222,7 @@ declare module "util" {
         export function isWebAssemblyCompiledModule(object: any): boolean;
     }
 
+    // TypeScript Version: 2.1
     export class TextDecoder {
         readonly encoding: string;
         readonly fatal: boolean;
diff --git a/types/node/v9/index.d.ts b/types/node/v9/index.d.ts
index 65c55878cd..def77c2337 100644
--- a/types/node/v9/index.d.ts
+++ b/types/node/v9/index.d.ts
@@ -5660,7 +5660,7 @@ declare module "util" {
     export namespace promisify {
         const custom: symbol;
     }
-
+    // TypeScript Version: 2.1
     export class TextDecoder {
         readonly encoding: string;
         readonly fatal: boolean;