---
title: React client hook in Server Component
---
## Why This Error Occurred
You are using a React client hook in a Server Component.
## Possible Ways to Fix It
Mark the component using the hook as a Client Component by adding `'use client'` at the top of the file.
### Before
```jsx filename="app/example.js"
import { useEffect } from 'react'
export default function Example() {
useEffect(() => {
console.log('in useEffect')
})
return <p>Hello world</p>
}
```
### After
```jsx filename="app/example.js"
'use client'
import { useEffect } from 'react'
export default function Example() {
useEffect(() => {
console.log('in useEffect')
})
return <p>Hello world</p>
}
```
## Useful Links
- [Server Components](/docs/app/getting-started/server-and-client-components)