diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 3e53c72931e..83472328ec4 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -398,6 +398,7 @@ pref("browser.tabs.loadDivertedInBackground", false);
 pref("browser.tabs.loadBookmarksInBackground", false);
 pref("browser.tabs.tabClipWidth", 140);
 pref("browser.tabs.animate", true);
+pref("browser.tabs.onTop", true);
 pref("browser.tabs.drawInTitlebar", true);
 
 // Where to show tab close buttons:
@@ -968,6 +969,7 @@ pref("services.sync.prefs.sync.browser.tabs.closeButtons", true);
 pref("services.sync.prefs.sync.browser.tabs.loadInBackground", true);
 pref("services.sync.prefs.sync.browser.tabs.warnOnClose", true);
 pref("services.sync.prefs.sync.browser.tabs.warnOnOpen", true);
+pref("services.sync.prefs.sync.browser.tabs.onTop", true);
 pref("services.sync.prefs.sync.browser.urlbar.autocomplete.enabled", true);
 pref("services.sync.prefs.sync.browser.urlbar.autoFill", true);
 pref("services.sync.prefs.sync.browser.urlbar.default.behavior", true);
diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 44033e8a057..eb93bc13a6b 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1364,7 +1364,7 @@ function BrowserStartup() {
 
   allTabs.readPref();
 
-  TabsOnTop.syncCommand();
+  TabsOnTop.init();
 
   BookmarksMenuButton.init();
 
@@ -5278,27 +5278,44 @@ function setToolbarVisibility(toolbar, isVisible) {
 }
 
 var TabsOnTop = {
-  toggle: function () {
-    this.enabled = !this.enabled;
+  init: function TabsOnTop_init() {
+    this.syncUI();
+    Services.prefs.addObserver(this._prefName, this, false);
   },
-  syncCommand: function () {
-    let enabled = this.enabled;
+
+  toggle: function () {
+    this.enabled = !Services.prefs.getBoolPref(this._prefName);
+  },
+
+  syncUI: function () {
+    let userEnabled = Services.prefs.getBoolPref(this._prefName);
+    let enabled = userEnabled && gBrowser.tabContainer.visible;
+
     document.getElementById("cmd_ToggleTabsOnTop")
-            .setAttribute("checked", enabled);
+            .setAttribute("checked", userEnabled);
+
     document.documentElement.setAttribute("tabsontop", enabled);
+    document.getElementById("navigator-toolbox").setAttribute("tabsontop", enabled);
     document.getElementById("TabsToolbar").setAttribute("tabsontop", enabled);
     gBrowser.tabContainer.setAttribute("tabsontop", enabled);
     TabsInTitlebar.allowedBy("tabs-on-top", enabled);
   },
+
   get enabled () {
     return gNavToolbox.getAttribute("tabsontop") == "true";
   },
-  set enabled (val) {
-    gNavToolbox.setAttribute("tabsontop", !!val);
-    this.syncCommand();
 
+  set enabled (val) {
+    Services.prefs.setBoolPref(this._prefName, !!val);
     return val;
-  }
+  },
+
+  observe: function (subject, topic, data) {
+    if (topic == "nsPref:changed")
+      this.syncUI();
+  },
+
+  _prefName: "browser.tabs.onTop"
 }
 
 var TabsInTitlebar = {
diff --git a/browser/base/content/browser.xul b/browser/base/content/browser.xul
index 531ac3b1074..e5284b74f85 100644
--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -444,9 +444,7 @@
 
   <toolbox id="navigator-toolbox"
            defaultmode="icons" mode="icons"
-           iconsize="large"
-           tabsontop="true"
-           persist="tabsontop">
+           iconsize="large">
     <!-- Menu -->
     <toolbar type="menubar" id="toolbar-menubar" class="chromeclass-menubar" customizable="true"
              defaultset="menubar-items"
diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index 68aa552a820..60f6e0cb504 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -2770,8 +2770,7 @@
           Services.prefs.addObserver("browser.tabs.", this._prefObserver, false);
           window.addEventListener("resize", this, false);
 
-          if (window.TabsInTitlebar)
-            TabsInTitlebar.allowedBy("tabs-visible", this.visible);
+          this._propagateVisibility();
         ]]>
       </constructor>
 
@@ -2839,17 +2838,30 @@
 
           this._container.collapsed = !val;
 
-          document.getElementById("menu_closeWindow").hidden = !val;
-          document.getElementById("menu_close").setAttribute("label",
-            this.tabbrowser.mStringBundle.getString(val ? "tabs.closeTab" : "tabs.close"));
-
-          if (window.TabsInTitlebar)
-            TabsInTitlebar.allowedBy("tabs-visible", val);
+          this._propagateVisibility();
 
           return val;
         ]]></setter>
       </property>
 
+      <method name="_propagateVisibility">
+        <body><![CDATA[
+          let visible = this.visible;
+
+          document.getElementById("menu_closeWindow").hidden = !visible;
+          document.getElementById("menu_close").setAttribute("label",
+            this.tabbrowser.mStringBundle.getString(visible ? "tabs.closeTab" : "tabs.close"));
+
+          goSetCommandEnabled("cmd_ToggleTabsOnTop", visible);
+
+          if (window.TabsOnTop)
+            TabsOnTop.syncUI();
+
+          if (window.TabsInTitlebar)
+            TabsInTitlebar.allowedBy("tabs-visible", visible);
+        ]]></body>
+      </method>
+
       <method name="updateVisibility">
         <body><![CDATA[
           if (this.childNodes.length - this.tabbrowser._removingTabs.length == 1)
diff --git a/browser/components/nsBrowserGlue.js b/browser/components/nsBrowserGlue.js
index e8ed1ddd49e..10d440f18b9 100644
--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -1100,7 +1100,7 @@ BrowserGlue.prototype = {
   },
 
   _migrateUI: function BG__migrateUI() {
-    const UI_VERSION = 5;
+    const UI_VERSION = 6;
     const BROWSER_DOCURL = "chrome://browser/content/browser.xul#";
     let currentUIVersion = 0;
     try {
@@ -1222,6 +1222,15 @@ BrowserGlue.prototype = {
       }
     }
 
+    if (currentUIVersion < 6) {
+      // convert tabsontop attribute to pref
+      let toolboxResource = this._rdf.GetResource(BROWSER_DOCURL + "navigator-toolbox");
+      let tabsOnTopResource = this._rdf.GetResource("tabsontop");
+      let tabsOnTopAttribute = this._getPersist(toolboxResource, tabsOnTopResource);
+      if (tabsOnTopAttribute)
+        Services.prefs.setBoolPref("browser.tabs.onTop", tabsOnTopAttribute == "true");
+    }
+
     if (this._dirty)
       this._dataSource.QueryInterface(Ci.nsIRDFRemoteDataSource).Flush();