diff --git a/packages/next/server/render.tsx b/packages/next/server/render.tsx
index 7d88ecd1a806a3b..196d88ae3c312fc 100644
--- a/packages/next/server/render.tsx
+++ b/packages/next/server/render.tsx
@@ -315,15 +315,12 @@ function renderDocument(
     styles: docProps.styles,
     head: docProps.head,
   }
-  return (
-    '<!DOCTYPE html>' +
-    ReactDOMServer.renderToStaticMarkup(
-      <AmpStateContext.Provider value={ampState}>
-        <HtmlContext.Provider value={htmlProps}>
-          <Document {...htmlProps} {...docProps} />
-        </HtmlContext.Provider>
-      </AmpStateContext.Provider>
-    )
+  return ReactDOMServer.renderToStaticMarkup(
+    <AmpStateContext.Provider value={ampState}>
+      <HtmlContext.Provider value={htmlProps}>
+        <Document {...htmlProps} {...docProps} />
+      </HtmlContext.Provider>
+    </AmpStateContext.Provider>
   )
 }
 
diff --git a/test/integration/production/test/index.test.js b/test/integration/production/test/index.test.js
index 591cba62d5b9047..0cc41f01f9a9a1a 100644
--- a/test/integration/production/test/index.test.js
+++ b/test/integration/production/test/index.test.js
@@ -917,6 +917,11 @@ describe('Production Usage', () => {
     expect(missing).toBe(false)
   })
 
+  it('should only have one DOCTYPE', async () => {
+    const html = await renderViaHTTP(appPort, '/')
+    expect(html).toMatch(/^<!DOCTYPE html><html/)
+  })
+
   if (global.browserName !== 'internet explorer') {
     it('should preserve query when hard navigating from page 404', async () => {
       const browser = await webdriver(appPort, '/')
