diff --git a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_Delaunay_triangulation_3.h b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_Delaunay_triangulation_3.h
index 16ad06bf42a..6cbcf48be1b 100644
--- a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_Delaunay_triangulation_3.h
+++ b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_Delaunay_triangulation_3.h
@@ -370,7 +370,7 @@ public:
             edge_to_delete = std::make_pair((*it)->vertex(k),(*it)->vertex(j));
           }
           Vertex_handle v_no = edge_to_delete.first;
-		  std::list<Vertex_handle>& vl = too_long_edges[v_no];
+          std::list<Vertex_handle>& vl = too_long_edges[v_no];
           sit = std::find(vl.begin(), vl.end(), edge_to_delete.second);
           if(sit != vl.end()) {
             vl.erase(sit);
@@ -407,7 +407,7 @@ public:
           p1 = construct_point((*it)->vertex(j)->point(), get_offset(*it, j));
           p2 = construct_point((*it)->vertex(k)->point(), get_offset(*it, k));
 
-		  std::list<Vertex_handle>& vl = too_long_edges[(*it)->vertex(j)];
+          std::list<Vertex_handle>& vl = too_long_edges[(*it)->vertex(j)];
 
           if((squared_distance(p1,p2) > edge_length_threshold)
              && (find(vl.begin(), vl.end(), edge_to_add.second)
diff --git a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3.h b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3.h
index 7e9584e48b0..8acdb35f190 100644
--- a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3.h
+++ b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_3.h
@@ -185,7 +185,7 @@ private:
                                                Virtual_vertex_map;
   typedef typename Virtual_vertex_map::const_iterator
                                                Virtual_vertex_map_it;
-  typedef std::map<Vertex_handle, std::vector<Vertex_handle > >
+  typedef boost::unordered_map<Vertex_handle, std::vector<Vertex_handle > >
                                                Virtual_vertex_reverse_map;
   typedef typename Virtual_vertex_reverse_map::const_iterator
                                                Virtual_vertex_reverse_map_it;