diff --git a/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java b/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java
index d801aeb..878cf9b 100644
--- a/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java
+++ b/G-Earth/src/main/java/gearth/extensions/ExtensionBase.java
@@ -169,9 +169,7 @@ public abstract class ExtensionBase extends IExtension {
      * The application got doubleclicked from the G-Earth interface. Doing something here is optional
      */
     @Override
-    void onClick() {
-
-    }
+    protected void onClick() {}
 
     @Override
     protected ExtensionInfo getInfoAnnotations() {
diff --git a/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java b/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java
index 6922c93..af2e9e8 100644
--- a/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java
+++ b/G-Earth/src/main/java/gearth/extensions/ExtensionForm.java
@@ -67,7 +67,7 @@ public abstract class ExtensionForm extends ExtensionBase {
     /**
      * The application got doubleclicked from the G-Earth interface. Doing something here is optional
      */
-    public void onClick(){
+    public final void onClick(){
         Platform.runLater(() -> {
             primaryStage.show();
             primaryStage.requestFocus();