--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -4504,16 +4504,17 @@ nsCSSFrameConstructor::FindXULTagData(El
 {
   if (aNameSpaceID != kNameSpaceID_XUL) {
     return nullptr;
   }
 
   static const FrameConstructionDataByTag sXULTagData[] = {
 #ifdef MOZ_XUL
     SCROLLABLE_XUL_CREATE(button, NS_NewButtonBoxFrame),
+    SCROLLABLE_XUL_CREATE(thumb, NS_NewButtonBoxFrame),
     SCROLLABLE_XUL_CREATE(checkbox, NS_NewButtonBoxFrame),
     SCROLLABLE_XUL_CREATE(radio, NS_NewButtonBoxFrame),
     SCROLLABLE_XUL_CREATE(autorepeatbutton, NS_NewAutoRepeatBoxFrame),
     SCROLLABLE_XUL_CREATE(titlebar, NS_NewTitleBarFrame),
     SCROLLABLE_XUL_CREATE(resizer, NS_NewResizerFrame),
     SIMPLE_XUL_CREATE(image, NS_NewImageBoxFrame),
     SIMPLE_XUL_CREATE(spring, NS_NewLeafBoxFrame),
     SIMPLE_XUL_CREATE(spacer, NS_NewLeafBoxFrame),

--- a/toolkit/content/minimal-xul.css
+++ b/toolkit/content/minimal-xul.css
@@ -82,17 +82,16 @@ resizer {
 /********** scrollbar **********/
 
 /* Scrollbars are never flipped even if BiDI kicks in. */
 scrollbar[orient="horizontal"] {
   direction: ltr;
 }
 
 thumb {
-  -moz-binding: url(chrome://global/content/bindings/scrollbar.xml#thumb);
   display: -moz-box !important;
 }
 
 .scale-thumb {
   -moz-binding: url(chrome://global/content/bindings/scale.xml#scalethumb);
 }
 
 scrollbar, scrollbarbutton, scrollcorner, slider, thumb, scale {

--- a/toolkit/content/widgets/scrollbar.xml
+++ b/toolkit/content/widgets/scrollbar.xml
@@ -3,18 +3,16 @@
    - 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/. -->
 
 
 <bindings id="scrollbarBindings"
    xmlns="http://www.mozilla.org/xbl"
    xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
    xmlns:xbl="http://www.mozilla.org/xbl">
-  
-  <binding id="thumb" extends="xul:button" />
 
   <binding id="scrollbar" bindToUntrustedContent="true">
     <content clickthrough="always">
       <xul:scrollbarbutton sbattr="scrollbar-up-top" type="decrement" xbl:inherits="curpos,maxpos,disabled,sborient=orient"/>
       <xul:scrollbarbutton sbattr="scrollbar-down-top" type="increment" xbl:inherits="curpos,maxpos,disabled,sborient=orient"/>
       <xul:slider flex="1" xbl:inherits="disabled,curpos,maxpos,pageincrement,increment,orient,sborient=orient">
         <xul:thumb sbattr="scrollbar-thumb" xbl:inherits="orient,sborient=orient,collapsed=disabled" 
                    align="center" pack="center"/>