diff --git a/mailnews/base/prefs/resources/locale/en-US/pref-notifications.dtd b/mailnews/base/prefs/resources/locale/en-US/pref-notifications.dtd
index 473ab630e36..7cdd1542a14 100644
--- a/mailnews/base/prefs/resources/locale/en-US/pref-notifications.dtd
+++ b/mailnews/base/prefs/resources/locale/en-US/pref-notifications.dtd
@@ -27,7 +27,7 @@ Rights Reserved.
 <!ENTITY preview.label                    "Preview">
 <!ENTITY preview.accesskey                "v">
 <!ENTITY systemsound.label                "System New Mail Sound">
-<!ENTITY customsound.label                "Custom wav file">
+<!ENTITY customsound.label                "Custom .wav file">
 <!ENTITY browse.label                     "Browse...">
 <!ENTITY browse.accesskey                 "B">
 <!ENTITY browse.title                     "Choose file">