diff --git a/types/webpack-serve/index.d.ts b/types/webpack-serve/index.d.ts
index 8e597097a7..222b8d8f09 100644
--- a/types/webpack-serve/index.d.ts
+++ b/types/webpack-serve/index.d.ts
@@ -16,7 +16,7 @@ export = WebpackServe;
 
 declare module 'webpack' {
   interface Configuration {
-    serve: WebpackServe.Options;
+    serve?: WebpackServe.Options;
   }
 }