--- a/calendar/base/content/dialogs/calendar-summary-dialog.xhtml
+++ b/calendar/base/content/dialogs/calendar-summary-dialog.xhtml
@@ -8,16 +8,17 @@
 <?xml-stylesheet type="text/css" href="chrome://calendar/skin/shared/calendar-alarms.css"?>
 <?xml-stylesheet type="text/css" href="chrome://calendar/skin/shared/calendar-attendees.css"?>
 <?xml-stylesheet type="text/css" href="chrome://messenger/skin/input-fields.css"?>
 <?xml-stylesheet type="text/css" href="chrome://calendar/skin/calendar-event-dialog.css"?>
 <?xml-stylesheet type="text/css" href="chrome://calendar/skin/shared/dialogs/calendar-event-dialog.css"?>
 <?xml-stylesheet type="text/css" href="chrome://messenger/skin/primaryToolbar.css"?>
 <?xml-stylesheet type="text/css" href="chrome://messenger/skin/messenger.css"?>
 <?xml-stylesheet type="text/css" href="chrome://calendar/content/widgets/calendar-item-summary.css"?>
+<?xml-stylesheet type="text/css" href="chrome://messenger/skin/themeableDialog.css"?>
 
 <!DOCTYPE window [
   <!ENTITY % globalDTD SYSTEM "chrome://calendar/locale/global.dtd" >
   <!ENTITY % calendarDTD SYSTEM "chrome://calendar/locale/calendar.dtd" >
   <!ENTITY % dialogDTD SYSTEM "chrome://calendar/locale/calendar-event-dialog.dtd" >
   <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd" >
   %globalDTD;
   %calendarDTD;
@@ -26,30 +27,32 @@
 ]>
 
 <!-- Dialog id is changed during execution to allow different Window-icons
      on this dialog. document.loadOverlay() will not work on this one. -->
 <window windowtype="Calendar:EventSummaryDialog"
         onload="onLoad()"
         onunload="onUnload()"
         persist="screenX screenY width height"
+        lightweightthemes="true"
         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
         xmlns:html="http://www.w3.org/1999/xhtml">
 
 <dialog id="calendar-summary-dialog">
 
   <!-- Javascript includes -->
   <script src="chrome://global/content/globalOverlay.js"/>
   <script src="chrome://global/content/editMenuOverlay.js"/>
   <script src="chrome://calendar/content/calendar-summary-dialog.js"/>
   <script src="chrome://calendar/content/calendar-dialog-utils.js"/>
   <script src="chrome://calendar/content/calendar-ui-utils.js"/>
   <script src="chrome://calendar/content/calendar-item-editing.js"/>
   <script src="chrome://calendar/content/calApplicationUtils.js"/>
   <script src="chrome://calendar/content/widgets/calendar-item-summary.js"/>
+  <script src="chrome://messenger/content/dialogShadowDom.js"/>
 
   <toolbox id="summary-toolbox"
            class="mail-toolbox"
            mode="full"
            defaultmode="full"
            iconsize="small"
            defaulticonsize="small"
            labelalign="end"