firebase x nextjs で ReferenceError: navigator is not defined

> Build error occurred
ReferenceError: navigator is not defined
    at Object.areCookiesEnabled (/vercel/28f5c7d0/node_modules/@firebase/util/dist/index.node.cjs.js:650:5)

// これを
if (!firebase.apps.length) {
  firebase.initializeApp(firebaseConfig);
  firebase.analytics();
}

// こう
if (typeof window !== 'undefined' && !firebase.apps.length) {
  firebase.initializeApp(firebaseConfig);
  firebase.analytics();
}