---
title: 'Invalid `assetPrefix`'
---

## Why This Error Occurred

The value of `assetPrefix` in `next.config.js` is set to something that is not a `string`.

## Possible Ways to Fix It

Ensure that `assetPrefix` is a `string`.

Example:

```js filename="next.config.js"
module.exports = {
  assetPrefix: '/',
}
```