diff --git a/GraphicsView/include/CGAL/Buffer_for_vao.h b/GraphicsView/include/CGAL/Buffer_for_vao.h
index b8ca1f752bb..0ff36cc96cd 100644
--- a/GraphicsView/include/CGAL/Buffer_for_vao.h
+++ b/GraphicsView/include/CGAL/Buffer_for_vao.h
@@ -35,7 +35,7 @@
 #include <vector>
 #include <cstdlib>
 #include <queue>
-#include <boost/unordered_map.hpp>
+#include <map>
 
 namespace CGAL
 {
@@ -606,8 +606,23 @@ protected:
     {
       P_traits cdt_traits(normal);
       CDT cdt(cdt_traits);
-      
       bool with_vertex_normal=(m_vertex_normals_for_face.size()==m_points_of_face.size());
+      Local_point p1, p2;
+        
+      // For each point of the face, store the list of adjacent points and the number of time
+      // the edge is found in the face. For an edge p1, p2, store edge min(p1,p2)->max(p1,p2)
+      std::map<Local_point, std::map<Local_point, unsigned int> > edges;
+      for (unsigned int i=0; i<m_points_of_face.size(); ++i)
+      {
+        p1=m_points_of_face[i];
+        p2=m_points_of_face[i==0?m_points_of_face.size()-1:i-1];
+        if (p2<p1) { std::swap(p1, p2); }
+        
+        if (edges.count(p1)==0)
+        { std::map<Local_point, unsigned int> m; m[p2]=1; edges[p1]=m; }
+        else if (edges[p1].count(p2)==0) { edges[p1][p2]=1; }
+        else { ++(edges[p1][p2]); }
+      }
       
       // (1) We insert all the edges as contraint in the CDT.
       typename CDT::Vertex_handle previous=NULL, first=NULL;
@@ -626,12 +641,22 @@ protected:
         { vh->info().index=m_indices_of_points_of_face[i]; }
         
         if(previous!=NULL && previous!=vh)
-        { cdt.insert_constraint(previous, vh); }
+        {
+          p1=m_points_of_face[i]; p2=m_points_of_face[i-1];
+          if (p2<p1) { std::swap(p1, p2); }
+          if ((edges[p1][p2])%2==1) // odd number of time => constraint
+          { cdt.insert_constraint(previous, vh); }
+        }
         previous=vh;
       }
       
       if (previous!=NULL && previous!=first)
-      { cdt.insert_constraint(previous, first); }
+      {
+        p1=m_points_of_face[m_points_of_face.size()-1]; p2=m_points_of_face[0];
+        if (p2<p1) std::swap(p1, p2);
+        if ((edges[p1][p2])%2==1) // odd number of time => constraint
+        { cdt.insert_constraint(previous, first); }
+      }
       
       // (2) We mark all external triangles
       // (2.1) We initialize is_external and is_process values