diff --git a/packages/next/build/webpack-config.ts b/packages/next/build/webpack-config.ts
index 050ee856dae7c6f..7d22744826b1559 100644
--- a/packages/next/build/webpack-config.ts
+++ b/packages/next/build/webpack-config.ts
@@ -2234,6 +2234,7 @@ export default async function getBaseWebpackConfig(
   }
 
   const configVars = JSON.stringify({
+    appDir: config.experimental.appDir,
     crossOrigin: config.crossOrigin,
     pageExtensions: pageExtensions,
     trailingSlash: config.trailingSlash,