---
title: 'Custom `_error` without /404'
---

## Why This Error Occurred

You added a custom `/_error` page without adding a custom `/404` page. Adding a custom `/_error` typically opts your application out of having the automatic static optimization applied to the 404 page.

## Possible Ways to Fix It

Add a `pages/404.js` with the 404 page you would like to show.

## Useful Links

- [Automatic Static Optimization](/docs/pages/building-your-application/rendering/automatic-static-optimization)
- [404 Page](/docs/pages/building-your-application/routing/custom-error#404-page)