Next.JS – “use client” directive produces an error

I’m having a super weird next.js issue. I just created a new project and any time I try to type "use client"; on a page, I’m met with a “SyntaxError: Unexpected token u in JSON at position 0”.

For reference, here’s my code:

"use client"

import { useRouter } from 'next/router';

export default function Page() {
  const router = useRouter();

  return (
    <div>
      <h1>Page</h1>
    </div>
  );
}

I’ve already tried to uninstall/reinstall create-next-app, but it doesn’t seem to help.

Thanks for any help!