diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/action/IAction.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/action/IAction.java
index 6389551c55..0e1666c022 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/action/IAction.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/action/IAction.java
@@ -13,6 +13,8 @@
  *****************************************************************************/
 package org.adempiere.webui.action;
 
+import org.zkoss.zul.Toolbarbutton;
+
 /**
  * Custom UI action provided through OSGi service. Implementation must be thread safe.   
  * @author hengsin
@@ -24,4 +26,12 @@ public interface IAction {
 	 * @param target
 	 */
 	public void execute(Object target);
+	
+	/**
+	 * you can customize toolbar button like add style, client javascript,...
+	 * @param toolbarButton
+	 */
+	public default void decorate(Toolbarbutton toolbarButton) {
+		
+	}
 }
diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/adwindow/ADWindowToolbar.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/adwindow/ADWindowToolbar.java
index 4517e39723..9ab46c45c1 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/adwindow/ADWindowToolbar.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/adwindow/ADWindowToolbar.java
@@ -245,7 +245,8 @@ public class ADWindowToolbar extends FToolbar implements EventListener<Event>
         		if (button.isCustomization()) {
         			String actionId = button.getActionClassName();
         			IServiceHolder<IAction> serviceHolder = Actions.getAction(actionId);
-        			if (serviceHolder != null && serviceHolder.getService() != null) {
+        			IAction action = serviceHolder.getService();
+        			if (serviceHolder != null && action != null) {
         				String labelKey = actionId + ".label";
         				String tooltipKey = actionId + ".tooltip";
         				String label = Msg.getMsg(Env.getCtx(), labelKey);
@@ -273,6 +274,7 @@ public class ADWindowToolbar extends FToolbar implements EventListener<Event>
         				toolbarCustomButtons.add(toolbarCustomBtn);
 
         				this.appendChild(btn);
+        				action.decorate(btn);
         			}
         		}
         		if (buttons.get(button.getComponentName()) != null) {