diff --git a/extension/js/common/browser/browser-msg.ts b/extension/js/common/browser/browser-msg.ts
index 15ffca67143..3321888a884 100644
--- a/extension/js/common/browser/browser-msg.ts
+++ b/extension/js/common/browser/browser-msg.ts
@@ -629,8 +629,8 @@ export class BrowserMsg {
   private static async sendAwait(destString: string | undefined, name: string, bm?: Dict<unknown>, awaitRes = false): Promise<Bm.Response> {
     bm = bm || {};
     // console.debug(`sendAwait ${name} to ${destString || 'bg'}`, bm);
-    const isBackgroundPage = await Env.isBackgroundPage();
-    if (isBackgroundPage && BrowserMsg.HANDLERS_REGISTERED_BACKGROUND && typeof destString === 'undefined') {
+    const isServiceWorker = await Env.isServiceWorker();
+    if (isServiceWorker && BrowserMsg.HANDLERS_REGISTERED_BACKGROUND && typeof destString === 'undefined') {
       // calling from bg script to bg script: skip messaging
       const handler: Bm.AsyncRespondingHandler = BrowserMsg.HANDLERS_REGISTERED_BACKGROUND[name];
       return await handler(bm);
@@ -647,7 +647,7 @@ export class BrowserMsg {
       stack: CatchHelper.stackTrace(),
     };
     // eslint-disable-next-line no-null/no-null
-    if (!(await Env.isBackgroundPage()) && msg.to !== null) {
+    if (!(await Env.isServiceWorker()) && msg.to !== null) {
       const validMsg: Bm.RawWithWindowExtensions = { ...msg, to: msg.to };
       // send via window messaging in parallel
       Catch.try(async () => {
@@ -695,9 +695,9 @@ export class BrowserMsg {
       };
       try {
         if (chrome.runtime) {
-          Env.isBackgroundPage()
-            .then(isBackgroundPage => {
-              if (isBackgroundPage) {
+          Env.isServiceWorker()
+            .then(isServiceWorker => {
+              if (isServiceWorker) {
                 chrome.tabs.query({ active: true, currentWindow: true }, tabs => {
                   for (const tab of tabs) {
                     chrome.tabs.sendMessage(Number(tab.id), msg, resolve);
diff --git a/extension/js/common/browser/chrome.ts b/extension/js/common/browser/chrome.ts
index c9cbca975f9..649948aa1c9 100644
--- a/extension/js/common/browser/chrome.ts
+++ b/extension/js/common/browser/chrome.ts
@@ -13,7 +13,7 @@ type ChromeStorageType = 'local' | 'session';
 
 const handleFatalErr = async (reason: 'storage_undefined', error: Error) => {
   try {
-    if (await Env.isBackgroundPage()) {
+    if (await Env.isServiceWorker()) {
       throw error;
     } else if (Env.isContentScript()) {
       console.error('Incomplete extension environment in content script', error);
diff --git a/extension/js/common/browser/env.ts b/extension/js/common/browser/env.ts
index d7b4828eafd..996a1a9f25a 100644
--- a/extension/js/common/browser/env.ts
+++ b/extension/js/common/browser/env.ts
@@ -42,13 +42,8 @@ export class Env {
   }
 
   // Check if the current context is a Service Worker
-  public static async isBackgroundPage() {
-    // In firefox, window&document is not null even in background page
-    if (typeof browser !== 'undefined' && typeof browser.runtime?.getBackgroundPage !== 'undefined') {
-      const backgroundPage = await browser.runtime.getBackgroundPage();
-      return backgroundPage === window;
-    }
-    return typeof window === 'undefined' && typeof document === 'undefined';
+  public static async isServiceWorker() {
+    return typeof window === 'undefined' && typeof importScripts === 'function';
   }
 
   public static isExtension() {