diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/DependencyComponent.java b/ganttzk/src/main/java/org/zkoss/ganttz/DependencyComponent.java
index 7641298af..24a02c272 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/DependencyComponent.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/DependencyComponent.java
@@ -56,6 +56,8 @@ public class DependencyComponent extends XulElement implements AfterCompose {
 
     private IConstraintViolationListener<GanttDate> violationListener;
 
+    private PropertyChangeListener visibilityChangeListener;
+
     private boolean violated = false;
 
     public DependencyComponent(TaskComponent source, TaskComponent destination,
@@ -192,4 +194,12 @@ public class DependencyComponent extends XulElement implements AfterCompose {
         return (source.isLimiting() || destination.isLimiting());
     }
 
+    public PropertyChangeListener getVisibilityChangeListener() {
+        return visibilityChangeListener;
+    }
+
+    public void setVisibilityChangeListener(PropertyChangeListener visibilityChangeListener) {
+        this.visibilityChangeListener = visibilityChangeListener;
+    }
+
 }
diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/DependencyList.java b/ganttzk/src/main/java/org/zkoss/ganttz/DependencyList.java
index 7b38a5f9a..c564afeae 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/DependencyList.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/DependencyList.java
@@ -149,6 +149,7 @@ public class DependencyList extends XulElement implements AfterCompose {
                 visibilityToggler);
         destination.getTask().addVisibilityPropertiesChangeListener(
                 visibilityToggler);
+        dependencyComponent.setVisibilityChangeListener(visibilityToggler);
         boolean dependencyMustBeVisible = visibilityToggler
                 .dependencyMustBeVisible();
         visibilityToggler.toggleDependencyExistence(dependencyMustBeVisible);
@@ -280,7 +281,7 @@ public class DependencyList extends XulElement implements AfterCompose {
         for (DependencyComponent dependencyComponent : DependencyList.this
                 .getDependencyComponents()) {
             if (dependencyComponent.contains(task)) {
-                this.removeChild(dependencyComponent);
+                removeDependencyComponent(dependencyComponent);
             }
         }
     }
@@ -289,8 +290,21 @@ public class DependencyList extends XulElement implements AfterCompose {
         for (DependencyComponent dependencyComponent : DependencyList.this
                 .getDependencyComponents()) {
             if (dependencyComponent.hasSameSourceAndDestination(dependency)) {
-                this.removeChild(dependencyComponent);
+                removeDependencyComponent(dependencyComponent);
             }
         }
     }
+
+    private void removeDependencyComponent(DependencyComponent dependencyComponent) {
+        //remove the visibility listener attached to the tasks
+        TaskComponent source = dependencyComponent.getSource();
+        TaskComponent destination = dependencyComponent.getDestination();
+        PropertyChangeListener listener =
+                dependencyComponent.getVisibilityChangeListener();
+        source.getTask().removeVisibilityPropertiesChangeListener(listener);
+        destination.getTask().removeVisibilityPropertiesChangeListener(listener);
+
+        //remove the dependency itself
+        this.removeChild(dependencyComponent);
+    }
 }
diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/data/Task.java b/ganttzk/src/main/java/org/zkoss/ganttz/data/Task.java
index d61a6cfe7..2600fcf15 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/data/Task.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/data/Task.java
@@ -309,6 +309,11 @@ public abstract class Task implements ITaskFundamentalProperties {
                 .removePropertyChangeListener(listener);
     }
 
+    public void removeVisibilityPropertiesChangeListener(
+            PropertyChangeListener listener) {
+        this.visibilityProperties.removePropertyChangeListener(listener);
+    }
+
     @Override
     public GanttDate getEndDate() {
         return fundamentalProperties.getEndDate();