diff --git a/Kinetic_data_structures/examples/Kinetic_data_structures/adding_a_certificate.C b/Kinetic_data_structures/examples/Kinetic_data_structures/adding_a_certificate.C
index 43ed521c6e4..3f0ce1cc28a 100644
--- a/Kinetic_data_structures/examples/Kinetic_data_structures/adding_a_certificate.C
+++ b/Kinetic_data_structures/examples/Kinetic_data_structures/adding_a_certificate.C
@@ -74,6 +74,8 @@ int main(int, char *[])
 
   std::ifstream in("data/points_2");
   in >> *tr.active_points_2_table_handle();
+  std::cout << "Read " << tr.active_points_2_table_handle()->size() 
+	    << " points" << std::endl;
   
   tr.simulator_handle()->set_current_time(tr.simulator_handle()->end_time());
 
diff --git a/Kinetic_data_structures/examples/Kinetic_data_structures/listener.C b/Kinetic_data_structures/examples/Kinetic_data_structures/listener.C
index aa547f9e395..6dd8122cd09 100644
--- a/Kinetic_data_structures/examples/Kinetic_data_structures/listener.C
+++ b/Kinetic_data_structures/examples/Kinetic_data_structures/listener.C
@@ -1,22 +1,25 @@
 #include <CGAL/Kinetic/Listener.h>
 #include <CGAL/Kinetic/Ref_counted.h>
 
+template <typename H>
+struct Listener_interface_impl
+  {
+  public:
+    typedef enum Notification_type {DATA_CHANGED}
+      Notification_type;
+   typedef H Notifier_handle;
+  };
+
+
 struct Notifier: public CGAL::Kinetic::Ref_counted<Notifier>
 {
 public:
   Notifier(): data_(0), listener_(NULL){}
 
-  struct Listener_interface
-  {
-  public:
-    typedef enum Notification_type {DATA_CHANGED}
-      Notification_type;
-    typedef Notifier::Handle Notifier_handle;
-  };
-
+  typedef CGAL::Kinetic::Ref_counted<Notifier> Base;
+  typedef Listener_interface_impl<typename Base::Handle> Listener_interface;
   typedef CGAL::Kinetic::Listener<Listener_interface> Listener;
-  friend class CGAL::Kinetic::Listener<Listener_interface>;
-  friend class Listener_interface;
+
 
   int data() const {return data_;}
   void set_data(int d) {
@@ -75,3 +78,4 @@ int main(int, char *[])
   }
   return EXIT_SUCCESS;
 }
+