diff --git a/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/package.json b/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/package.json
index d11bb98..b48bb68 100644
--- a/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/package.json
+++ b/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/package.json
@@ -1,6 +1,6 @@
 {
   "name": "aspnet-webpack",
-  "version": "2.0.1",
+  "version": "2.0.2",
   "description": "Helpers for using Webpack in ASP.NET Core projects. Works in conjunction with the Microsoft.AspNetCore.SpaServices NuGet package.",
   "main": "index.js",
   "scripts": {
diff --git a/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts b/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts
index bc8c21a..502ecaa 100644
--- a/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts
+++ b/src/Microsoft.AspNetCore.SpaServices/npm/aspnet-webpack/src/WebpackDevMiddleware.ts
@@ -262,9 +262,9 @@ export function createWebpackDevServer(callback: CreateDevServerCallback, option
         webpackConfigExport = webpackConfigExport(options.suppliedOptions.EnvParam);
     }
 
-    const webpackConfigThenable: Thenable<WebpackConfigOrArray> = isThenable(webpackConfigExport)
+    const webpackConfigThenable = isThenable<WebpackConfigOrArray>(webpackConfigExport)
         ? webpackConfigExport
-        : { then: callback => callback(webpackConfigExport) };
+        : { then: callback => callback(webpackConfigExport) } as Thenable<WebpackConfigOrArray>;
 
     webpackConfigThenable.then(webpackConfigResolved => {
         const webpackConfigArray = webpackConfigResolved instanceof Array ? webpackConfigResolved : [webpackConfigResolved];