diff --git a/suite/common/pref/pref.xul b/suite/common/pref/pref.xul
index e6583ab77f53..c9cc4fa250ce 100644
--- a/suite/common/pref/pref.xul
+++ b/suite/common/pref/pref.xul
@@ -55,8 +55,11 @@
   <script type="application/x-javascript" src="chrome://help/content/contextHelp.js"/>
 
   <hbox flex="1">
-    <!-- tree sidebar -->
-    <tree id="prefsTree" style="width: 13em;"/>
+    <vbox>
+      <label value="&categoryHeader;"/>
+      <!-- tree sidebar -->
+      <tree id="prefsTree" style="width: 13em;" flex="1"/>
+    </vbox>
     <vbox flex="1">
       <dialogheader id="header"/>
       <iframe id="panelFrame" name="panelFrame" style="width: 0px" flex="1"/>
diff --git a/suite/common/pref/preftree.xul b/suite/common/pref/preftree.xul
index ad8031b9fb20..7bdf060c60bb 100644
--- a/suite/common/pref/preftree.xul
+++ b/suite/common/pref/preftree.xul
@@ -39,7 +39,7 @@
 <tree id="prefsTree" seltype="single" hidecolumnpicker="true"
           onselect="if( hPrefWindow ) hPrefWindow.switchPage();">
   <treecols>
-    <treecol id="categoryCol" label="&category.label;" flex="1" primary="true"/>
+    <treecol id="categoryCol" flex="1" primary="true" hideheader="true"/>
   </treecols>
   <treechildren id="panelChildren">
     <treeitem container="true" id="appearance">
diff --git a/suite/locales/en-US/chrome/common/pref/pref.dtd b/suite/locales/en-US/chrome/common/pref/pref.dtd
index 3bf00c064e64..4b1dd9b83f37 100644
--- a/suite/locales/en-US/chrome/common/pref/pref.dtd
+++ b/suite/locales/en-US/chrome/common/pref/pref.dtd
@@ -2,6 +2,7 @@
 
 <!-- LOCALIZATION NOTE : FILE UI for the outer parts of the Prefs dialog -->
 <!ENTITY  prefWindow.title            "Preferences">
+<!ENTITY  categoryHeader              "Category">
 
 <!-- LOCALIZATION NOTE : this is part of an inline-style attribute on the
      preference dialog's <window> node, which specifies the width and height
diff --git a/suite/locales/en-US/chrome/common/pref/preftree.dtd b/suite/locales/en-US/chrome/common/pref/preftree.dtd
index 8432110b09fb..bb9d0e1a191b 100644
--- a/suite/locales/en-US/chrome/common/pref/preftree.dtd
+++ b/suite/locales/en-US/chrome/common/pref/preftree.dtd
@@ -1,7 +1,5 @@
 <!-- extracted from content/preftree.xul -->
 
-<!ENTITY category.label "Category">
-
 <!--LOCALIZATION NOTE : FILE Lists preferences categories that appear on the left of the preferences dialog -->
 <!ENTITY appear.label "Appearance">
 <!ENTITY fonts.label "Fonts">