diff --git a/types/webpack-env/index.d.ts b/types/webpack-env/index.d.ts
index dc5241b487..9949e17c91 100644
--- a/types/webpack-env/index.d.ts
+++ b/types/webpack-env/index.d.ts
@@ -68,7 +68,7 @@ declare namespace __WebpackModuleApi {
         id: string;
         filename: string;
         loaded: boolean;
-        parent: NodeModule | null;
+        parent: NodeModule | null | undefined;
         children: NodeModule[];
         hot?: Hot;
     }
diff --git a/types/webpack-env/webpack-env-tests.ts b/types/webpack-env/webpack-env-tests.ts
index 987a8f49fe..af5a6d0080 100644
--- a/types/webpack-env/webpack-env-tests.ts
+++ b/types/webpack-env/webpack-env-tests.ts
@@ -1,4 +1,4 @@
-
+/// <reference types="node"/>
 
 interface SomeModule {
     someMethod(): void;