diff --git a/src/base/combination/combo.js b/src/base/combination/combo.js
index 6c3ee97513..62dde79f8d 100644
--- a/src/base/combination/combo.js
+++ b/src/base/combination/combo.js
@@ -8,7 +8,7 @@
         _defaultConfig: function () {
             var conf = BI.Combo.superclass._defaultConfig.apply(this, arguments);
             return BI.extend(conf, {
-                baseCls: (conf.baseCls || "") + " bi-combo",
+                baseCls: (conf.baseCls || "") + " bi-combo" + (BI.isIE() ? " hack" : ""),
                 trigger: "click",
                 toggle: true,
                 direction: "bottom", // top||bottom||left||right||top,left||top,right||bottom,left||bottom,right||right,innerRight||right,innerLeft||innerRight||innerLeft
diff --git a/src/widget/downlist/combo.downlist.js b/src/widget/downlist/combo.downlist.js
index a998064c74..24c87c336c 100644
--- a/src/widget/downlist/combo.downlist.js
+++ b/src/widget/downlist/combo.downlist.js
@@ -4,7 +4,7 @@
 BI.DownListCombo = BI.inherit(BI.Widget, {
     _defaultConfig: function () {
         return BI.extend(BI.DownListCombo.superclass._defaultConfig.apply(this, arguments), {
-            baseCls: "bi-down-list-combo" + (BI.isIE() ? " hack" : ""),
+            baseCls: "bi-down-list-combo",
             height: 24,
             items: [],
             adjustLength: 0,