diff --git a/src/case/button/icon/icon.trigger.js b/src/case/button/icon/icon.trigger.js
index 6f7c2a1ee..daa76b121 100644
--- a/src/case/button/icon/icon.trigger.js
+++ b/src/case/button/icon/icon.trigger.js
@@ -10,10 +10,10 @@ BI.TriggerIconButton = BI.inherit(BI.IconButton, {
     _defaultConfig: function () {
         var conf = BI.TriggerIconButton.superclass._defaultConfig.apply(this, arguments);
         return BI.extend(conf, {
-            baseCls: (conf.baseCls || "") + " bi-trigger-icon-button",
+            baseCls: (conf.baseCls || "") + " bi-trigger-icon-button overflow-hidden",
             extraCls: "pull-down-font"
         });
     }
 });
 BI.TriggerIconButton.EVENT_CHANGE = BI.IconButton.EVENT_CHANGE;
-BI.shortcut("bi.trigger_icon_button", BI.TriggerIconButton);
\ No newline at end of file
+BI.shortcut("bi.trigger_icon_button", BI.TriggerIconButton);