diff --git a/addon/chrome/content/dialogs/promptservice.js b/addon/chrome/content/dialogs/promptservice.js
index 84d5b9c0..4fd57c60 100644
--- a/addon/chrome/content/dialogs/promptservice.js
+++ b/addon/chrome/content/dialogs/promptservice.js
@@ -44,6 +44,11 @@ function prompt_init() {
   }
   documentElement = document.documentElement;
 
+  const dialog = documentElement;
+  dialog.addEventListener("dialogaccept", prompt_deinit.bind(dialog, 0));
+  dialog.addEventListener("dialogcancel", prompt_deinit.bind(dialog, 1));
+  dialog.addEventListener("dialogextra1", prompt_extra1.bind(dialog, 2));
+
   dialogParams = window.arguments[0].QueryInterface(Ci.nsIDialogParamBlock);
   document.title = dialogParams.GetString(0);
 
@@ -127,7 +132,6 @@ function prompt_init() {
 
   // Set and focus default button
   var dButton = buttons[dialogParams.GetInt(0)] ?? "accept";
-  var dialog = documentElement;
   dialog.defaultButton = dButton;
   if (gHideElmParam == TMP_HIDE_MENUANDTEXT) { // hide menulist & text box and set focus to default Button
     document.getElementById("space_before_checkbox").hidden = true;
diff --git a/addon/chrome/content/dialogs/promptservice.xhtml b/addon/chrome/content/dialogs/promptservice.xhtml
index 3fe0bb00..63e5c7ad 100644
--- a/addon/chrome/content/dialogs/promptservice.xhtml
+++ b/addon/chrome/content/dialogs/promptservice.xhtml
@@ -1,5 +1,6 @@
 <?xml version="1.0"?>
 <?xml-stylesheet href="chrome://browser/skin/" type="text/css"?>
+<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
 
 <!DOCTYPE dialog [
   <!ENTITY % pref-tabmixDTD SYSTEM "chrome://tabmixplus/locale/pref-tabmix.dtd">
@@ -12,21 +13,11 @@
    resizable="no"
    onload="prompt_init();"
    buttons="accept, cancel, extra1"
-   ondialogaccept="return prompt_deinit(0);"
-   ondialogcancel="return prompt_deinit(1);"
-   ondialogextra1="return prompt_extra1(2);"
    buttonpack="center"
    style="-moz-user-focus: ignore; padding: 8px 10px 10px 8px;">
 
-   <script type="text/javascript"><![CDATA[
-    let t = document.getElementsByTagName("dialog")[0];
-    let f = new Function("event", t.getAttribute("ondialogaccept"));
-    t.addEventListener("dialogaccept", event => f.call(t, event));
-    t.addEventListener("dialogcancel", event => f.call(t, event));
-    t.addEventListener("dialogextra1", event => f.call(t, event));
-    ]]></script>
-   <script type="application/javascript" src="chrome://tabmixplus/content/utils.js"/>
-   <script type="application/javascript" src="chrome://tabmixplus/content/dialogs/promptservice.js"/>
+  <script type="application/javascript" src="chrome://tabmixplus/content/utils.js"/>
+  <script type="application/javascript" src="chrome://tabmixplus/content/dialogs/promptservice.js"/>
 
   <hbox >
     <hbox align="start">
diff --git a/addon/chrome/content/overlay/autoReload.js b/addon/chrome/content/overlay/autoReload.js
index a8ed1f4b..faba63e2 100644
--- a/addon/chrome/content/overlay/autoReload.js
+++ b/addon/chrome/content/overlay/autoReload.js
@@ -7,6 +7,7 @@ const {TabmixSvc} = ChromeUtils.import("chrome://tabmix-resource/content/TabmixS
 const gPref = TabmixSvc.prefBranch;
 
 function load() {
+  document.documentElement.addEventListener("dialogaccept", accept.bind(null));
   const customReloadTime = gPref.getIntPref("reload_time");
   document.getElementById("autoreload_minutes").value = String(Math.floor(customReloadTime / 60));
   document.getElementById("autoreload_seconds").value = String(customReloadTime % 60);
diff --git a/addon/chrome/content/overlay/autoReload.xhtml b/addon/chrome/content/overlay/autoReload.xhtml
index 3b8d669f..d12a6bdb 100644
--- a/addon/chrome/content/overlay/autoReload.xhtml
+++ b/addon/chrome/content/overlay/autoReload.xhtml
@@ -16,17 +16,11 @@
 <dialog id="reloadevery_custom_dialog"
         title="&specifyreload.label;"
         buttons="accept,cancel"
-        ondialogaccept="accept();"
         onload="load();"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         xmlns:html="http://www.w3.org/1999/xhtml"
         tabindex="0">
 
-  <script type="text/javascript"><![CDATA[
-    let t = document.getElementsByTagName("dialog")[0];
-    let f = new Function("event", t.getAttribute("ondialogaccept"));
-    t.addEventListener("dialogaccept", event => f.call(t, event));
-    ]]></script>
   <script type="application/javascript" src="chrome://tabmixplus/content/preferences/numberinput.js"/>
   <script type="application/javascript" src="chrome://tabmixplus/content/overlay/autoReload.js"/>
 
diff --git a/addon/chrome/content/preferences/subdialogs/pref-appearance.js b/addon/chrome/content/preferences/subdialogs/pref-appearance.js
index 5d3419d6..01af2442 100644
--- a/addon/chrome/content/preferences/subdialogs/pref-appearance.js
+++ b/addon/chrome/content/preferences/subdialogs/pref-appearance.js
@@ -11,6 +11,11 @@ const tabstyles = {
     $("stylestabs").selectedIndex = Tabmix.prefs.prefHasUserValue(this.pref) ?
       Tabmix.prefs.getIntPref(this.pref) : 0;
 
+    window.addEventListener("dialogcancel", () => tabstyles.cancel());
+    window.addEventListener("dialogaccept", () => tabstyles.save());
+    window.addEventListener("dialogextra1", () => tabstyles.openHelp());
+    window.addEventListener("dialogextra2", () => tabstyles.toggleRGB_visibility());
+
     const dialog = document.querySelector("dialog");
     if (!window.opener && !Tabmix.getTopWin()) {
       dialog.getButton("extra1").disabled = true;
diff --git a/addon/chrome/content/preferences/subdialogs/pref-appearance.xhtml b/addon/chrome/content/preferences/subdialogs/pref-appearance.xhtml
index 363e1077..5a8982ff 100644
--- a/addon/chrome/content/preferences/subdialogs/pref-appearance.xhtml
+++ b/addon/chrome/content/preferences/subdialogs/pref-appearance.xhtml
@@ -18,19 +18,8 @@
         xmlns:html="http://www.w3.org/1999/xhtml"
         title="&styles.label;"
         persist="screenX screenY hide-RGB"
-        onload="tabstyles.init();"
-        ondialogcancel="tabstyles.cancel();"
-        ondialogaccept="tabstyles.save();"
-        ondialogextra2="tabstyles.toggleRGB_visibility();">
+        onload="tabstyles.init();">
 <dialog buttons="accept,cancel,extra1,extra2">
-
-   <script type="text/javascript"><![CDATA[
-    /* global tabstyles */
-    this.addEventListener("dialogcancel", () => tabstyles.cancel());
-    this.addEventListener("dialogaccept", () => tabstyles.save());
-    this.addEventListener("dialogextra1", () => tabstyles.openHelp());
-    this.addEventListener("dialogextra2", () => tabstyles.toggleRGB_visibility());
-    ]]></script>
    <script type="application/javascript" src="chrome://tabmixplus/content/preferences/subdialogs/pref-appearance-ce.js"/>
    <script type="application/javascript" src="chrome://tabmixplus/content/preferences/checkbox_tmp-ce.js"/>
    <script type="application/javascript" src="chrome://tabmixplus/content/utils.js"/>
diff --git a/addon/chrome/content/preferences/subdialogs/pref-filetype.js b/addon/chrome/content/preferences/subdialogs/pref-filetype.js
index f613fb07..b36a69b2 100644
--- a/addon/chrome/content/preferences/subdialogs/pref-filetype.js
+++ b/addon/chrome/content/preferences/subdialogs/pref-filetype.js
@@ -13,6 +13,9 @@ var del;
 var add;
 
 function Init() {
+  window.addEventListener("dialogaccept", () => Save());
+  window.addEventListener("dialogextra1", () => window.opener.openHelp('links#file-type-editor'));
+
   const prefwindow = window.opener.document.querySelector("prefwindow");
   const button = document.querySelector('[dlgtype="extra1"]');
   prefwindow.setButtonLabel("help", button);
diff --git a/addon/chrome/content/preferences/subdialogs/pref-filetype.xhtml b/addon/chrome/content/preferences/subdialogs/pref-filetype.xhtml
index 2eb590ba..84d23139 100644
--- a/addon/chrome/content/preferences/subdialogs/pref-filetype.xhtml
+++ b/addon/chrome/content/preferences/subdialogs/pref-filetype.xhtml
@@ -19,11 +19,6 @@
         onload="Init()"
         persist="screenX screenY">
 <dialog buttons="accept,cancel,extra1">
-   <script type="text/javascript"><![CDATA[
-     /* global Save */
-     this.addEventListener("dialogaccept", () => Save());
-     this.addEventListener("dialogextra1", () => window.opener.openHelp('links#file-type-editor'));
-   ]]></script>
    <script type="application/javascript" src="chrome://tabmixplus/content/utils.js"/>
    <script type="application/javascript" src="chrome://tabmixplus/content/preferences/subdialogs/pref-filetype.js"/>
 
diff --git a/types/preferences.d.ts b/types/preferences.d.ts
index 53b88b38..69767a3d 100644
--- a/types/preferences.d.ts
+++ b/types/preferences.d.ts
@@ -602,7 +602,7 @@ interface PanelItemButton extends HTMLButtonElement {
 interface QuerySelectorMap {
   ".content-box": HTMLElement;
   deck: HTMLElement;
-  dialog: HTMLDialogElement;
+  dialog: HTMLDialogElement & {ownerGlobal: Window};
   description: HTMLElement;
   'panel-item[action="preferences"]': HTMLElement & {button: PanelItemButton};
   prefwindow: PrefWindowClass;