diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/Planner.java b/ganttzk/src/main/java/org/zkoss/ganttz/Planner.java
index a63a4c12b..1d2984df6 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/Planner.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/Planner.java
@@ -877,7 +877,9 @@ public class Planner extends HtmlMacroComponent  {
         if (taskList != null) {
             taskList.updateCompletion(progressType);
             // FIXME Bug #1270
-            taskList.invalidate();
+            for (TaskComponent each : taskList.getTaskComponents()) {
+                each.invalidate();
+            }
         }
     }
 
diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/TaskList.java b/ganttzk/src/main/java/org/zkoss/ganttz/TaskList.java
index 451bbda6b..f1b66e0aa 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/TaskList.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/TaskList.java
@@ -198,7 +198,7 @@ public class TaskList extends XulElement implements AfterCompose {
         return getTimeTrackerComponent().getTimeTracker();
     }
 
-    private List<TaskComponent> getTaskComponents() {
+    protected List<TaskComponent> getTaskComponents() {
         ArrayList<TaskComponent> result = new ArrayList<TaskComponent>();
         for (Object child : getChildren()) {
             if (child instanceof TaskRow) {