--- title: No Document Import in Page --- > Prevent importing `next/document` outside of `pages/_document.js`. ## Why This Error Occurred `next/document` was imported in a page outside of `pages/_document.js` (or `pages/_document.tsx` if you are using TypeScript). This can cause unexpected issues in your application. ## Possible Ways to Fix It Only import and use `next/document` within `pages/_document.js` (or `pages/_document.tsx`) to override the default `Document` component: ```jsx filename="pages/_document.js" import Document, { Html, Head, Main, NextScript } from 'next/document' class MyDocument extends Document { //... } export default MyDocument ``` ## Useful Links - [Custom Document](/docs/pages/building-your-application/routing/custom-document)