diff --git a/webextensions/background/background.js b/webextensions/background/background.js
index b89073e8..695806e7 100644
--- a/webextensions/background/background.js
+++ b/webextensions/background/background.js
@@ -411,6 +411,7 @@ async function notifyReady() {
     configs.cachedExternalAddons = addons;
 }
 
+
 // migration
 
 browser.runtime.onInstalled.addListener(details => {
@@ -466,6 +467,37 @@ async function notifyUpdatedFromLegacy() {
   });
 }
 
+function initNotifyFeaturesTab(tab) {
+  const type = /\?(legacy|installed|updated)/i.test(tab.url) && String(RegExp.$1).toLowerCase();
+
+  const title = `${browser.i18n.getMessage('extensionName')} ${browser.runtime.getManifest().version}`;
+  const description = browser.i18n.getMessage(
+    type == 'legacy' ?
+      'message_updatedFromLegacy_description' :
+      'message_newFeatures_description'
+  );
+
+  browser.tabs.executeScript(tab.id, {
+    code: `
+      document.querySelector('#title').textContent = document.title = ${JSON.stringify(title)};
+      document.querySelector('#description').innerHTML = ${JSON.stringify(description)};
+    `
+  });
+}
+
+browser.tabs.onUpdated.addListener(
+  (_tabId, updateInfo, tab) => {
+    if (updateInfo.status != 'complete')
+      return;
+    initNotifyFeaturesTab(tab);
+  },
+  { properties: ['status'],
+    urls: [browser.extension.getURL(`resources/notify-features.html*`)] }
+);
+browser.tabs.query({ url: browser.extension.getURL(`resources/notify-features.html*`) })
+  .then(tabs => tabs.forEach(initNotifyFeaturesTab));
+
+
 // This section should be removed and define those context-fill icons
 // statically on manifest.json after Firefox ESR66 (or 67) is released.
 // See also: https://github.com/piroor/multipletab/issues/215
diff --git a/webextensions/resources/module/.eslintrc.js b/webextensions/resources/module/.eslintrc.js
deleted file mode 100644
index d3ba6b09..00000000
--- a/webextensions/resources/module/.eslintrc.js
+++ /dev/null
@@ -1,15 +0,0 @@
-/*
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-*/
-/*eslint-env commonjs*/
-/*eslint quote-props: ['error', "always"] */
-
-'use strict';
-
-module.exports = {
-  'extends': [
-    '../../tools/eslint/for-module.js',
-  ],
-};
diff --git a/webextensions/resources/module/notify-features.js b/webextensions/resources/module/notify-features.js
deleted file mode 100644
index ba8db4f3..00000000
--- a/webextensions/resources/module/notify-features.js
+++ /dev/null
@@ -1,20 +0,0 @@
-/*
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-*/
-'use strict';
-
-window.addEventListener('DOMContentLoaded', () => {
-  const type = /(legacy|installed|updated)/i.test(location.search) && String(RegExp.$1).toLowerCase();
-
-  const title = `${browser.i18n.getMessage('extensionName')} ${browser.runtime.getManifest().version}`;
-  const description = browser.i18n.getMessage(
-    type == 'legacy' ?
-      'message_updatedFromLegacy_description' :
-      'message_newFeatures_description'
-  );
-
-  document.querySelector('#title').textContent = document.title = title;
-  document.querySelector('#description').innerHTML = description;
-}, { once: true });
diff --git a/webextensions/resources/notify-features.html b/webextensions/resources/notify-features.html
index 96fa7fbe..0a2729ca 100644
--- a/webextensions/resources/notify-features.html
+++ b/webextensions/resources/notify-features.html
@@ -2,7 +2,6 @@
 <meta charset="UTF-8">
 <link rel="icon" href="./16x16-light.svg">
 <title></title>
-<script type="module" src="./module/notify-features.js"></script>
 <style type="text/css">
   body {
     background: white;