diff --git a/Installation/CHANGES b/Installation/CHANGES
index 865c2d44107..6fd46119173 100644
--- a/Installation/CHANGES
+++ b/Installation/CHANGES
@@ -20,6 +20,8 @@ Additional supported platforms:
 
 3- Kernels
 
+- We recommend that you use the object_cast() function instead of assign()
+  to extract an object from a CGAL::Object, for efficiency reasons.
 - The Kernel archetypes provided by the 2D/3D linear kernel have been removed.
 - The deprecated linear kernel functors Construct_supporting_line_2 and
   Construct_supporting_line_3 have been removed.
diff --git a/Min_circle_2/demo/Min_circle_2/min_circle_2.cpp b/Min_circle_2/demo/Min_circle_2/min_circle_2.cpp
index 022ed8a73eb..dcb21b177d8 100644
--- a/Min_circle_2/demo/Min_circle_2/min_circle_2.cpp
+++ b/Min_circle_2/demo/Min_circle_2/min_circle_2.cpp
@@ -184,9 +184,8 @@ public slots:
 private slots:
   void get_new_object(CGAL::Object obj)
   {
-    Point_2 p;
-    if(CGAL::assign(p,obj)) {
-      list_of_points.push_back(p);
+    if(const Point_2 *p = CGAL::object_cast<Point_2>(&obj)) {
+      list_of_points.push_back(*p);
       something_changed();
     }
   };
diff --git a/Min_ellipse_2/demo/Min_ellipse_2/min_ellipse_2.cpp b/Min_ellipse_2/demo/Min_ellipse_2/min_ellipse_2.cpp
index ab9ce96e208..87834fcfbb7 100644
--- a/Min_ellipse_2/demo/Min_ellipse_2/min_ellipse_2.cpp
+++ b/Min_ellipse_2/demo/Min_ellipse_2/min_ellipse_2.cpp
@@ -193,9 +193,8 @@ public slots:
 private slots:
   void get_new_object(CGAL::Object obj)
   {
-    Point_2 p;
-    if(CGAL::assign(p,obj)) {
-      list_of_points.push_back(p);
+    if(const Point_2 *p = CGAL::object_cast<Point_2>(&obj)) {
+      list_of_points.push_back(*p);
       something_changed();
     }
   };
diff --git a/Min_quadrilateral_2/demo/Min_quadrilateral_2/min_quadrilateral_2.cpp b/Min_quadrilateral_2/demo/Min_quadrilateral_2/min_quadrilateral_2.cpp
index 97d98e25677..c0efd9c3d08 100644
--- a/Min_quadrilateral_2/demo/Min_quadrilateral_2/min_quadrilateral_2.cpp
+++ b/Min_quadrilateral_2/demo/Min_quadrilateral_2/min_quadrilateral_2.cpp
@@ -160,9 +160,8 @@ public slots:
 private slots:
   void get_new_object(CGAL::Object obj)
   {
-    Point_2 p;
-    if(CGAL::assign(p,obj)) {
-      list_of_points.push_back(p);
+    if(const Point_2 *p = CGAL::object_cast<Point_2>(&obj)) {
+      list_of_points.push_back(*p);
       something_changed();
     }
   };