diff --git a/packages/next/build/babel/plugins/next-page-config.ts b/packages/next/build/babel/plugins/next-page-config.ts
index 6ba8bef1a5a3e..481e046d7bdb3 100644
--- a/packages/next/build/babel/plugins/next-page-config.ts
+++ b/packages/next/build/babel/plugins/next-page-config.ts
@@ -110,6 +110,19 @@ export default function nextPageConfig({
           t.returnStatement(t.stringLiteral(inlineGipIdentifier)),
         ])
       },
+      // handles class { static async getInitialProps() {} }
+      ClassMethod(path, state: ConfigState) {
+        if (!state.setupInlining) return
+        if (
+          (path.node.key && (path.node.key as BabelTypes.Identifier).name) !==
+          'getInitialProps'
+        )
+          return
+
+        path.node.body = t.blockStatement([
+          t.returnStatement(t.stringLiteral(inlineGipIdentifier)),
+        ])
+      },
     },
   }
 }
diff --git a/packages/next/export/index.js b/packages/next/export/index.js
index 58ec0e62568ad..4f51627dbbb17 100644
--- a/packages/next/export/index.js
+++ b/packages/next/export/index.js
@@ -105,7 +105,8 @@ export default async function (dir, options, configuration) {
     dev: false,
     staticMarkup: false,
     hotReloader: null,
-    canonicalBase: (nextConfig.amp && nextConfig.amp.canonicalBase) || ''
+    canonicalBase: (nextConfig.amp && nextConfig.amp.canonicalBase) || '',
+    isModern: nextConfig.modern
   }
 
   const { serverRuntimeConfig, publicRuntimeConfig } = nextConfig
diff --git a/packages/next/export/worker.js b/packages/next/export/worker.js
index f089e8607ed22..256890cb8a4bb 100644
--- a/packages/next/export/worker.js
+++ b/packages/next/export/worker.js
@@ -119,7 +119,8 @@ process.on(
             'static',
             buildId,
             'pages',
-            (path === '/' ? 'index' : path) + '.js'
+            (path === '/' ? 'index' : path) +
+              `${renderOpts.isModern ? '.es6' : ''}.js`
           )
 
           const bundleContent = await readFileP(bundlePath, 'utf8')