# Fix the 'can't resolve module' error in Next.js

> Fix the Next.js Module not found: Can't resolve 'fs' error, which happens when you import a Node module helper but never call it inside getStaticProps().

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2021-05-05 | Topics: [Next.js](https://flaviocopes.com/tags/next/) | Canonical: https://flaviocopes.com/nextjs-module-not-found/

I ran into this issue with [Next.js](https://flaviocopes.com/nextjs/):

> Module not found: Can't resolve 'fs'

In a Next.js page your can import methods from a file that loads [Node.js](https://flaviocopes.com/nodejs/) modules.

This is fine, as long as you also **use** the imported method in getStaticProps().

Example, I had this code:

```js
import { getData } from '../lib/data'

//...

export async function getStaticProps() {
  const data = getData()
  return {
    props: {
      data,
    },
  }
}
```

When I commented `const data = getData()`, Next started giving me the error ` 'fs' module not found` because `fs` was the first module I imported in `lib/data`.

It might happen with any other Node library you import first.

This happens because anything in getStaticProps() is just called when ran in a server environment, but if we don't invoke the Node.js function in there, Next.js can't know that.