diff --git a/webpack-dev-middleware/index.d.ts b/webpack-dev-middleware/index.d.ts
index e173d4e3d4..471a0f92ba 100644
--- a/webpack-dev-middleware/index.d.ts
+++ b/webpack-dev-middleware/index.d.ts
@@ -8,7 +8,10 @@ import { compiler } from 'webpack';
 
 export = WebpackDevMiddleware;
 
-declare function WebpackDevMiddleware(compiler: compiler.Compiler, options: WebpackDevMiddleware.Options): WebpackDevMiddleware.WebpackDevMiddleware & NextHandleFunction;
+declare function WebpackDevMiddleware(
+	compiler: compiler.Compiler,
+	options?: WebpackDevMiddleware.Options
+): WebpackDevMiddleware.WebpackDevMiddleware & NextHandleFunction;
 
 declare namespace WebpackDevMiddleware {
 	interface Options {
@@ -39,7 +42,7 @@ declare namespace WebpackDevMiddleware {
 
 	type Reporter = (reporterOptions: ReporterOptions) => void;
 
-	type Logger = (message: any) => void;
+	type Logger = (message?: any, ...optionalParams: any[]) => void;
 
 	interface WebpackDevMiddleware {
 		close(callback?: () => void): void;
diff --git a/webpack-dev-middleware/webpack-dev-middleware-tests.ts b/webpack-dev-middleware/webpack-dev-middleware-tests.ts
index b204fbe5d8..63d32332b5 100644
--- a/webpack-dev-middleware/webpack-dev-middleware-tests.ts
+++ b/webpack-dev-middleware/webpack-dev-middleware-tests.ts
@@ -3,7 +3,10 @@ import * as webpack from 'webpack';
 import * as webpackDevMiddleware from 'webpack-dev-middleware';
 
 const compiler = webpack({});
-const webpackDevMiddlewareInstance = webpackDevMiddleware(compiler, {
+
+let webpackDevMiddlewareInstance = webpackDevMiddleware(compiler);
+
+webpackDevMiddlewareInstance = webpackDevMiddleware(compiler, {
 	noInfo: false,
 	quiet: false,
 	lazy: true,