--- a/browser/components/preferences/in-content/search.xul
+++ b/browser/components/preferences/in-content/search.xul
@@ -67,17 +67,17 @@
       </vbox>
     </groupbox>
 
     <groupbox id="oneClickSearchProvidersGroup" data-category="paneSearch">
       <caption><label>&oneClickSearchEngines.label;</label></caption>
       <description>&chooseWhichOneToDisplay2.label;</description>
 
       <tree id="engineList" flex="1" rows="8" hidecolumnpicker="true" editable="true"
-            seltype="single">
+            seltype="single" allowunderflowscroll="true">
         <treechildren id="engineChildren" flex="1"/>
         <treecols>
           <treecol id="engineShown" type="checkbox" editable="true" sortable="false"/>
           <treecol id="engineName" flex="4" label="&engineNameColumn.label;" sortable="false"/>
           <treecol id="engineKeyword" flex="1" label="&engineKeywordColumn.label;" editable="true"
                    sortable="false"/>
         </treecols>
       </tree>