diff --git a/Apollonius_graph_2/changes.txt b/Apollonius_graph_2/changes.txt
index 911740f9744..16251fa015a 100644
--- a/Apollonius_graph_2/changes.txt
+++ b/Apollonius_graph_2/changes.txt
@@ -2,6 +2,8 @@
 - fixes in #includes: correct files are now included
 - added mixed traits classes, filtered and non-filtered
 - removed obsolete code
+- replaced call to assert by call to CGAL_assertion in
+  Apollonius_graph_2_impl.h
 
 19 July 2006:  Menelaos Karavelas
 - further CGALization of new traits functors/classes
diff --git a/Apollonius_graph_2/include/CGAL/Apollonius_graph_2/Apollonius_graph_2_impl.h b/Apollonius_graph_2/include/CGAL/Apollonius_graph_2/Apollonius_graph_2_impl.h
index 14bedecf7e1..7211042b596 100644
--- a/Apollonius_graph_2/include/CGAL/Apollonius_graph_2/Apollonius_graph_2_impl.h
+++ b/Apollonius_graph_2/include/CGAL/Apollonius_graph_2/Apollonius_graph_2_impl.h
@@ -1794,7 +1794,7 @@ remove_degree_d_vertex(Vertex_handle v)
 
   Vertex_handle vn = ag_small.nearest_neighbor(v->site().point());
 
-  assert( vn != Vertex_handle() );
+  CGAL_assertion( vn != Vertex_handle() );
 
   List l;
   Face_map fm;