diff --git a/src/mscz.ts b/src/mscz.ts
index 0ef500c..cec07c2 100644
--- a/src/mscz.ts
+++ b/src/mscz.ts
@@ -1,10 +1,10 @@
 
-import { saveAs, assertRes } from './utils'
+import { saveAs, assertRes, getFetch } from './utils'
 import { ScoreInfo } from './scoreinfo'
 
 const MSCZ_BUF_SYM = Symbol('msczBufferP')
 
-export const fetchMscz = async (scoreinfo: ScoreInfo, _fetch = fetch): Promise<ArrayBuffer> => {
+export const fetchMscz = async (scoreinfo: ScoreInfo, _fetch = getFetch()): Promise<ArrayBuffer> => {
   let msczBufferP = scoreinfo.store.get(MSCZ_BUF_SYM) as Promise<ArrayBuffer> | undefined
 
   if (!msczBufferP) {
diff --git a/src/utils.ts b/src/utils.ts
index 86cd3ce..d1e71f5 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,5 +1,6 @@
 
 import FileSaver from 'file-saver/dist/FileSaver.js'
+import isNodeJs from 'detect-node'
 
 export const saveAs: typeof import('file-saver').saveAs = FileSaver.saveAs
 
@@ -13,6 +14,15 @@ export const getIndexPath = (id: number): string => {
   return indexN.join('/')
 }
 
+export const getFetch = (): typeof fetch => {
+  if (!isNodeJs) {
+    return fetch
+  } else {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+    return require('node-fetch')
+  }
+}
+
 export const fetchData = async (url: string, init?: RequestInit): Promise<Uint8Array> => {
   const r = await fetch(url, init)
   const data = await r.arrayBuffer()
@@ -37,6 +47,7 @@ export const useTimeout = async <T> (promise: T | Promise<T>, ms: number): Promi
 }
 
 export const getSandboxWindow = (): Window => {
+  if (typeof document === 'undefined') return {} as any as Window
   const iframe = document.createElement('iframe')
   iframe.style.display = 'none'
   document.body.append(iframe)