diff --git a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_on_surface_base_2.h b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_on_surface_base_2.h
index b35b9eabcba..fec3cccb1bf 100644
--- a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_on_surface_base_2.h
+++ b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_on_surface_base_2.h
@@ -226,6 +226,22 @@ public:
       delete m_traits;
   }
 
+  void simplify(const Polygon_2& pgn, Polygon_with_holes_2& res)
+  {
+    typedef Gps_polygon_simplifier<Aos_2>  Simplifier;
+
+    Aos_2*  arr = new Aos_2();
+
+    Simplifier simp(*arr, *m_traits);
+    simp.simplify(pgn);
+    _remove_redundant_edges(arr);
+    Self gps(arr);
+    gps._reset_faces();
+  
+    typedef Oneset_iterator<Polygon_with_holes_2>    OutputItr;
+    OutputItr oi (res);
+    gps.polygons_with_holes(oi);
+  }
 
   // insert a simple polygon
   void insert(const Polygon_2& pgn)
diff --git a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_polygon_simplifier.h b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_polygon_simplifier.h
index 139c3ffe09a..a4b93819189 100644
--- a/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_polygon_simplifier.h
+++ b/Boolean_set_operations_2/include/CGAL/Boolean_set_operations_2/Gps_polygon_simplifier.h
@@ -51,6 +51,7 @@ class Gps_polygon_simplifier
   typedef typename Arrangement_2::Halfedge_handle     Halfedge_handle;
   typedef typename Arrangement_2::Halfedge_iterator   Halfedge_iterator;
   typedef typename Arrangement_2::Face_handle         Face_handle;
+  typedef typename Arrangement_2::Face_iterator       Face_iterator;
   typedef typename Arrangement_2::Edge_iterator       Edge_iterator;
   typedef typename Arrangement_2::Vertex_handle       Vertex_handle;
   typedef typename Arrangement_2::Ccb_halfedge_const_circulator 
@@ -119,9 +120,18 @@ public:
    
     m_sweep_line.sweep(curves_list.begin(), curves_list.end());
 
-    m_faces_hash[m_arr->unbounded_face()] = 0; 
+    // we use the first face with out outer ccbs. This assumpsion should
+    // be fixed when we can make a face with no outer ccb to a face with
+    // outer ccb.
+    Face_iterator it;
+    for (it = m_arr->faces_begin(); it != m_arr->faces_end(); ++it)
+      if (it->number_of_outer_ccbs() == 0)
+        break;
+    CGAL_assertion(it != m_arr->faces_end());
+   
+    m_faces_hash[it] = 0; 
     Bfs_visitor visitor(&m_edges_hash, &m_faces_hash, 1);
-    visitor.visit_ubf(m_arr->unbounded_face(), 0);
+    visitor.visit_ubf(it, 0);
     Bfs_scanner scanner(visitor);
     scanner.scan(*m_arr);
     visitor.after_scan(*m_arr);