diff --git a/packages/next/build/webpack/loaders/next-middleware-ssr-loader/render.ts b/packages/next/build/webpack/loaders/next-middleware-ssr-loader/render.ts
index beefd6dcb861..826752d4201e 100644
--- a/packages/next/build/webpack/loaders/next-middleware-ssr-loader/render.ts
+++ b/packages/next/build/webpack/loaders/next-middleware-ssr-loader/render.ts
@@ -12,20 +12,6 @@ import {
   WebNextResponse,
 } from '../../../../server/base-http/web'
 
-const createHeaders = (args?: any) => ({
-  ...args,
-  'x-middleware-ssr': '1',
-  'Cache-Control': 'no-cache, no-store, max-age=0, must-revalidate',
-})
-
-function sendError(req: any, error: Error) {
-  const defaultMessage = 'An error occurred while rendering ' + req.url + '.'
-  return new Response((error && error.message) || defaultMessage, {
-    status: 500,
-    headers: createHeaders(),
-  })
-}
-
 // Polyfilled for `path-browserify` inside the Web Server.
 process.cwd = () => ''
 
@@ -135,19 +121,14 @@ export function getRender({
 
     // Preflight request
     if (request.method === 'HEAD') {
+      // Hint the client that the matched route is a SSR page.
       return new Response(null, {
-        headers: createHeaders(),
+        headers: {
+          'x-middleware-ssr': '1',
+        },
       })
     }
 
-    // @TODO: We should move this into server/render.
-    if (Document.getInitialProps) {
-      const err = new Error(
-        '`getInitialProps` in Document component is not supported with the Edge Runtime.'
-      )
-      return sendError(req, err)
-    }
-
     const renderServerComponentData = isServerComponent
       ? query.__flight__ !== undefined
       : false
diff --git a/packages/next/server/dev/hot-reloader.ts b/packages/next/server/dev/hot-reloader.ts
index 92847d189629..0c6454f8072b 100644
--- a/packages/next/server/dev/hot-reloader.ts
+++ b/packages/next/server/dev/hot-reloader.ts
@@ -336,6 +336,8 @@ export default class HotReloader {
           )
         )
 
+      const hasEdgeRuntimePages = this.runtime === 'edge'
+
       return webpackConfigSpan
         .traceChild('generate-webpack-config')
         .traceAsyncFn(() =>
@@ -363,7 +365,7 @@ export default class HotReloader {
               }),
               // For the edge runtime, we need an extra compiler to generate the
               // web-targeted server bundle for now.
-              this.runtime === 'edge'
+              hasEdgeRuntimePages
                 ? getBaseWebpackConfig(this.dir, {
                     dev: true,
                     isServer: true,
diff --git a/packages/next/server/render.tsx b/packages/next/server/render.tsx
index 4dbb76ffec85..d8dbd4976893 100644
--- a/packages/next/server/render.tsx
+++ b/packages/next/server/render.tsx
@@ -1249,6 +1249,13 @@ export async function renderToHTML(
    */
   const generateStaticHTML = supportsDynamicHTML !== true
   const renderDocument = async () => {
+    if (runtime === 'edge' && Document.getInitialProps) {
+      // In the Edge runtime, Document.getInitialProps isn't supported.
+      throw new Error(
+        '`getInitialProps` in Document component is not supported with the Edge Runtime.'
+      )
+    }
+
     if (!runtime && Document.getInitialProps) {
       const renderPage: RenderPage = (
         options: ComponentsEnhancer = {}