diff --git a/Triangulation/include/CGAL/Triangulation_data_structure.h b/Triangulation/include/CGAL/Triangulation_data_structure.h
index 4a02ad29d53..233db52c37c 100644
--- a/Triangulation/include/CGAL/Triangulation_data_structure.h
+++ b/Triangulation/include/CGAL/Triangulation_data_structure.h
@@ -383,7 +383,7 @@ public:
     template< typename OutputIterator >
     Full_cell_handle insert_in_tagged_hole(Vertex_handle, Facet, OutputIterator);
 
-    Vertex_handle insert_increase_dimension(Vertex_handle); /* Concept */
+    Vertex_handle insert_increase_dimension(Vertex_handle=Vertex_handle()); /* Concept */
 
 private:
 
@@ -1131,7 +1131,7 @@ void Triangulation_data_structure<Dim, Vb, Fcb>
 template <class Dim, class Vb, class Fcb>
 typename Triangulation_data_structure<Dim, Vb, Fcb>::Vertex_handle
 Triangulation_data_structure<Dim, Vb, Fcb>
-::insert_increase_dimension(Vertex_handle star = Vertex_handle()) /* Concept */
+::insert_increase_dimension(Vertex_handle star) /* Concept */
 {
     const int prev_cur_dim = current_dimension();
     CGAL_precondition(prev_cur_dim < maximal_dimension());