diff --git a/calendar/base/content/calendar-alarm-dialog.js b/calendar/base/content/calendar-alarm-dialog.js
index 223c43d611cc..bef95d7eb747 100644
--- a/calendar/base/content/calendar-alarm-dialog.js
+++ b/calendar/base/content/calendar-alarm-dialog.js
@@ -46,6 +46,21 @@ function addAlarm(event)
   alarmWidget.item = event;
 
   alarmList.appendChild(alarmWidget);
+
+   var prefService = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefService);
+   var calendarPrefs = prefService.getBranch("calendar.");
+
+   var playSound = calendarPrefs.getBoolPref("alarms.playsound");
+   if (playSound) {
+     try {
+       var soundURL = makeURL(calendarPrefs.getCharPref("alarms.soundURL"));
+       var sound = Components.classes["@mozilla.org/sound;1"].createInstance(Components.interfaces.nsISound);
+       sound.init();
+       sound.play(soundURL);
+     } catch (ex) {
+       dump("unable to play sound...\n" + ex + "\n");
+     }
+   }
 }
 
 function removeAlarm(event)
diff --git a/calendar/base/content/calendar-alarm-dialog.xul b/calendar/base/content/calendar-alarm-dialog.xul
index 37db6f34ac60..ee4cf69a0a14 100644
--- a/calendar/base/content/calendar-alarm-dialog.xul
+++ b/calendar/base/content/calendar-alarm-dialog.xul
@@ -24,6 +24,7 @@
 
 <!-- Javascript includes -->
 <script type="application/x-javascript" src="chrome://calendar/content/calendar-alarm-dialog.js"/>
+<script type="application/x-javascript" src="chrome://calendar/content/calendarUtils.js"/>
 
 <!-- The dialog -->
     <vbox id="alarmlist" flex="1" style="overflow: auto;">