diff --git a/mozilla/calendar/prototypes/wcap/sun-calendar-event-dialog-reminder.xul b/mozilla/calendar/prototypes/wcap/sun-calendar-event-dialog-reminder.xul
index 64482e0a86d..09a0acb8092 100644
--- a/mozilla/calendar/prototypes/wcap/sun-calendar-event-dialog-reminder.xul
+++ b/mozilla/calendar/prototypes/wcap/sun-calendar-event-dialog-reminder.xul
@@ -68,7 +68,7 @@
       <row/>
     </rows>
     <columns>
-      <listbox id="reminder-listbox" seltype="single" onselect="onReminderSelected()">
+      <listbox id="reminder-listbox" seltype="single" onselect="onReminderSelected()" flex="1">
         <listitem/>
       </listbox>
       <column>