diff --git a/ext/bg/js/settings/popup-preview-frame-main.js b/ext/bg/js/settings/popup-preview-frame-main.js
new file mode 100644
index 00000000..e6e4727f
--- /dev/null
+++ b/ext/bg/js/settings/popup-preview-frame-main.js
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2019-2020  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* global
+ * SettingsPopupPreview
+ */
+
+async function main() {
+    const instance = new SettingsPopupPreview();
+    await instance.prepare();
+}
+
+main();
diff --git a/ext/bg/js/settings/popup-preview-frame.js b/ext/bg/js/settings/popup-preview-frame.js
index fba114e2..420a7c5a 100644
--- a/ext/bg/js/settings/popup-preview-frame.js
+++ b/ext/bg/js/settings/popup-preview-frame.js
@@ -41,12 +41,6 @@ class SettingsPopupPreview {
         ]);
     }
 
-    static create() {
-        const instance = new SettingsPopupPreview();
-        instance.prepare();
-        return instance;
-    }
-
     async prepare() {
         // Setup events
         window.addEventListener('message', this.onMessage.bind(this), false);
@@ -178,8 +172,3 @@ class SettingsPopupPreview {
         this.setInfoVisible(!this.popupShown);
     }
 }
-
-SettingsPopupPreview.instance = SettingsPopupPreview.create();
-
-
-
diff --git a/ext/bg/settings-popup-preview.html b/ext/bg/settings-popup-preview.html
index f33ecedf..66475b7c 100644
--- a/ext/bg/settings-popup-preview.html
+++ b/ext/bg/settings-popup-preview.html
@@ -129,5 +129,7 @@
         <script src="/fg/js/popup-proxy-host.js"></script>
         <script src="/fg/js/frontend.js"></script>
         <script src="/bg/js/settings/popup-preview-frame.js"></script>
+
+        <script src="/bg/js/settings/popup-preview-frame-main.js"></script>
     </body>
 </html>