diff --git a/content/treestyletab/config.xul b/content/treestyletab/config.xul
index 853958b0..ce24cd7d 100644
--- a/content/treestyletab/config.xul
+++ b/content/treestyletab/config.xul
@@ -40,6 +40,9 @@
 		<preference id="extensions.treestyletab.tabbar.invertScrollbar"
 			name="extensions.treestyletab.tabbar.invertScrollbar"
 			type="bool"/>
+		<preference id="extensions.treestyletab.tabbar.invertClosebox"
+			name="extensions.treestyletab.tabbar.invertClosebox"
+			type="bool"/>
 		<preference id="extensions.treestyletab.tabbar.invertUI"
 			name="extensions.treestyletab.tabbar.invertUI"
 			type="bool"/>
@@ -98,6 +101,9 @@
 			</grid>
 		</radiogroup>
 		<hbox align="center">
+			<checkbox id="extensions.treestyletab.tabbar.invertClosebox-check"
+				preference="extensions.treestyletab.tabbar.invertClosebox"
+				label="&config.tabbar.invertClosebox;"/>
 			<checkbox id="extensions.treestyletab.allowSubtreeCollapseExpand-check"
 				preference="extensions.treestyletab.allowSubtreeCollapseExpand"
 				label="&config.allowSubtreeCollapseExpand;"/>
diff --git a/locale/de-DE/treestyletab/treestyletab.dtd b/locale/de-DE/treestyletab/treestyletab.dtd
index 20762b1f..13c3ebcb 100644
--- a/locale/de-DE/treestyletab/treestyletab.dtd
+++ b/locale/de-DE/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "Oben (Firefox Standard)">
 <!ENTITY config.tabbar.position.bottom  "Unten">
 <!ENTITY config.tabbar.invertScrollbar  "Scrollbar ganz links anzeigen">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "Reihenfolge der Tabs umdrehen">
 <!ENTITY config.enableSubtreeIndent         "Tabs einrücken">
 <!ENTITY config.allowSubtreeCollapseExpand  "Auf- und Einklappen von Zweigen erlauben">
diff --git a/locale/en-US/treestyletab/treestyletab.dtd b/locale/en-US/treestyletab/treestyletab.dtd
index fdae9447..0510f4ac 100644
--- a/locale/en-US/treestyletab/treestyletab.dtd
+++ b/locale/en-US/treestyletab/treestyletab.dtd
@@ -10,7 +10,8 @@
 <!ENTITY config.tabbar.position.right   "Rightside">
 <!ENTITY config.tabbar.position.top     "Top (Firefox default)">
 <!ENTITY config.tabbar.position.bottom  "Bottom">
-<!ENTITY config.tabbar.invertScrollbar  "Show scrollbar leftmost">
+<!ENTITY config.tabbar.invertScrollbar  "Show scrollbar leftside">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "Invert tab appearance">
 <!ENTITY config.enableSubtreeIndent         "Indent tabs">
 <!ENTITY config.allowSubtreeCollapseExpand  "Allow to collapse/expand sub tree of tabs">
diff --git a/locale/es-ES/treestyletab/treestyletab.dtd b/locale/es-ES/treestyletab/treestyletab.dtd
index 00f161e1..ff79a8ea 100644
--- a/locale/es-ES/treestyletab/treestyletab.dtd
+++ b/locale/es-ES/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "Encima (Predeterminado en Firefox)">
 <!ENTITY config.tabbar.position.bottom  "Debajo">
 <!ENTITY config.tabbar.invertScrollbar  "Mostrar barra de desplazamiento a la izquierda">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "Invertir apariencia de pestaña">
 <!ENTITY config.enableSubtreeIndent         "Añadir margen a las pestañas">
 <!ENTITY config.allowSubtreeCollapseExpand  "Permitir colapsar/expandir los sub-árboles de las pestañas">
diff --git a/locale/it-IT/treestyletab/treestyletab.dtd b/locale/it-IT/treestyletab/treestyletab.dtd
index 5fa45cd4..05905f41 100644
--- a/locale/it-IT/treestyletab/treestyletab.dtd
+++ b/locale/it-IT/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "in alto (comportamento predefinito di Firefox)">
 <!ENTITY config.tabbar.position.bottom  "in basso">
 <!ENTITY config.tabbar.invertScrollbar  "Visualizza la barra di scorrimento all&apos;estrema sinistra">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "Inverti la visualizzazione delle schede">
 <!ENTITY config.enableSubtreeIndent         "Indenta sottoschede">
 <!ENTITY config.allowSubtreeCollapseExpand  "Permetti di contrarre/espandere sottoalberi delle schede">
diff --git a/locale/ja/treestyletab/treestyletab.dtd b/locale/ja/treestyletab/treestyletab.dtd
index a04e971f..13110b68 100644
--- a/locale/ja/treestyletab/treestyletab.dtd
+++ b/locale/ja/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "上（Firefox初期状態）">
 <!ENTITY config.tabbar.position.bottom  "下">
 <!ENTITY config.tabbar.invertScrollbar  "スクロールバーを左に表示">
+<!ENTITY config.tabbar.invertClosebox   "タブのクローズボックスを左に表示">
 <!ENTITY config.tabbar.invertUI         "タブを左右反転">
 <!ENTITY config.enableSubtreeIndent         "タブをインデント表示する">
 <!ENTITY config.allowSubtreeCollapseExpand  "サブツリーを折りたためるようにする">
diff --git a/locale/pl-PL/treestyletab/treestyletab.dtd b/locale/pl-PL/treestyletab/treestyletab.dtd
index 1353695c..5347cd49 100644
--- a/locale/pl-PL/treestyletab/treestyletab.dtd
+++ b/locale/pl-PL/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "Na górze (wartość domyślna)">
 <!ENTITY config.tabbar.position.bottom  "Na dole">
 <!ENTITY config.tabbar.invertScrollbar  "Wyświetlaj pasek przewijania po lewej">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "Odwróć wyświetlanie kart">
 <!ENTITY config.enableSubtreeIndent         "Stosuj wcięcia">
 <!ENTITY config.allowSubtreeCollapseExpand  "Zezwalaj na zwijanie/rozwijanie drzewa kart">
diff --git a/locale/ru-RU/treestyletab/treestyletab.dtd b/locale/ru-RU/treestyletab/treestyletab.dtd
index 9f7ca22e..5db633d7 100755
--- a/locale/ru-RU/treestyletab/treestyletab.dtd
+++ b/locale/ru-RU/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "Сверху (в Firefox по умолчанию)">
 <!ENTITY config.tabbar.position.bottom  "Снизу">
 <!ENTITY config.tabbar.invertScrollbar  "Показывать скроллинг у левого края">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "Инвертировать вид вкладок">
 <!ENTITY config.enableSubtreeIndent         "Отступы вкладок">
 <!ENTITY config.allowSubtreeCollapseExpand  "Разрешить сворачивать/разворачивать поддеревья вкладок">
diff --git a/locale/zh-CN/treestyletab/treestyletab.dtd b/locale/zh-CN/treestyletab/treestyletab.dtd
index 1be42bbd..eadc90e3 100644
--- a/locale/zh-CN/treestyletab/treestyletab.dtd
+++ b/locale/zh-CN/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "顶部 (Firefox 默认)">
 <!ENTITY config.tabbar.position.bottom  "底部">
 <!ENTITY config.tabbar.invertScrollbar  "在最左侧显示滚动条">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "反转标签外观">
 <!ENTITY config.enableSubtreeIndent         "缩进标签">
 <!ENTITY config.allowSubtreeCollapseExpand  "允许折叠/展开标签子树">
diff --git a/locale/zh-TW/treestyletab/treestyletab.dtd b/locale/zh-TW/treestyletab/treestyletab.dtd
index 337ece59..30c9a7e8 100644
--- a/locale/zh-TW/treestyletab/treestyletab.dtd
+++ b/locale/zh-TW/treestyletab/treestyletab.dtd
@@ -11,6 +11,7 @@
 <!ENTITY config.tabbar.position.top     "上端（Firefox 預設）">
 <!ENTITY config.tabbar.position.bottom  "下端">
 <!ENTITY config.tabbar.invertScrollbar  "在最左側顯示捲軸列">
+<!ENTITY config.tabbar.invertClosebox   "Show closebox at leftside in each tab">
 <!ENTITY config.tabbar.invertUI         "左右反轉分頁外觀">
 <!ENTITY config.enableSubtreeIndent         "縮進分頁">
 <!ENTITY config.allowSubtreeCollapseExpand  "允許摺疊 / 展開樹狀子目錄">