diff --git a/lib/ace/autocomplete/popup.js b/lib/ace/autocomplete/popup.js
index a3034364..891cf1e8 100644
--- a/lib/ace/autocomplete/popup.js
+++ b/lib/ace/autocomplete/popup.js
@@ -138,10 +138,10 @@ var AcePopup = function(parentNode) {
         if (selected == t.selectedNode)
             return;
         if (t.selectedNode)
-            dom.removeCssClass(t.selectedNode, "selected");
+            dom.removeCssClass(t.selectedNode, "ace_selected");
         t.selectedNode = selected;
         if (selected)
-            dom.addCssClass(selected, "selected");
+            dom.addCssClass(selected, "ace_selected");
     });
     var hideHoverMarker = function() { setHoverMarker(-1) };
     var setHoverMarker = function(row, suppressRedraw) {