diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/data/DefaultFundamentalProperties.java b/ganttzk/src/main/java/org/zkoss/ganttz/data/DefaultFundamentalProperties.java
index 009e8f5a7..a5b62021f 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/data/DefaultFundamentalProperties.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/data/DefaultFundamentalProperties.java
@@ -194,4 +194,9 @@ public class DefaultFundamentalProperties implements ITaskFundamentalProperties
         return false;
     }
 
+    @Override
+    public Date getConsolidatedline() {
+        return null;
+    }
+
 }