diff --git a/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_traits_3.h b/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_traits_3.h
index c4c59b2141d..b964807c19f 100644
--- a/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_traits_3.h
+++ b/Convex_hull_3/doc/Convex_hull_3/CGAL/Convex_hull_traits_3.h
@@ -8,11 +8,12 @@ The class `Convex_hull_traits_3` serves as a traits class for the function
 function when `R` is a kernel with exact predicates but inexact constructions 
 (note that the type `Plane_3` is a triple of `Point_3` and not `R::Plane_3`). 
 
+\tparam MFG must be a ,model of  MutableFaceGraph
 \cgalModels `ConvexHullTraits_3`
 \cgalModels `IsStronglyConvexTraits_3` 
 
 */
-template< typename R >
+  template< typename R, typename MFG = Polyhedron_3<R> >
 class Convex_hull_traits_3 {
 public:
 
@@ -42,7 +43,7 @@ typedef unspecified_type Plane_3;
 /*!
 
 */ 
-typedef Polyhedron_3<R> Polyhedron_3;
+typedef MFG Polyhedron_3;
 
 /*!
 
diff --git a/Convex_hull_3/doc/Convex_hull_3/CGAL/convex_hull_3.h b/Convex_hull_3/doc/Convex_hull_3/CGAL/convex_hull_3.h
index e6806b2bfab..57266cf61ae 100644
--- a/Convex_hull_3/doc/Convex_hull_3/CGAL/convex_hull_3.h
+++ b/Convex_hull_3/doc/Convex_hull_3/CGAL/convex_hull_3.h
@@ -17,7 +17,7 @@ that is `P` will contain only triangular facets.
 \tparam Polyhedron_3 must be a model of `MutableFaceGraph`.
 \tparam Traits must be a model of the concept `ConvexHullTraits_3`. 
 For the purposes of checking the postcondition that the convex hull 
-is valid, `Traits` should also be a model of the concept 
+is valid, `Traits` must also be a model of the concept 
 `IsStronglyConvexTraits_3`. 
 
 
@@ -53,7 +53,7 @@ in case the result is a polyhedron.
 \tparam InputIterator must be an input iterator with a value type  equivalent to `Traits::Point_3`. 
 \tparam Traits must be model of the concept `ConvexHullTraits_3`. 
 For the purposes of checking the postcondition that the convex hull 
-is valid, `Traits` should also be a model of the concept 
+is valid, `Traits` must also be a model of the concept 
 `IsStronglyConvexTraits_3`.   Furthermore, `Traits` must define a type `Polyhedron_3` that is a model of 
 `MutableFaceGraph`. 
 
diff --git a/Convex_hull_3/include/CGAL/Convex_hull_traits_3.h b/Convex_hull_3/include/CGAL/Convex_hull_traits_3.h
index 79876b18a1f..c115507f45c 100644
--- a/Convex_hull_3/include/CGAL/Convex_hull_traits_3.h
+++ b/Convex_hull_3/include/CGAL/Convex_hull_traits_3.h
@@ -185,20 +185,20 @@ struct Convex_hull_traits_base_3<R_, Tag_true>{
 };
 
 
-template <class R_, class Has_filtered_predicates_tag = Tag_false>
+  template <class R_, class Polyhedron = Polyhedron_3<R_>, class Has_filtered_predicates_tag = Tag_false>
 class Convex_hull_traits_3 :
   public Convex_hull_traits_base_3<R_, Has_filtered_predicates_tag>
 {
  public:  
   typedef R_                                     R;
-  typedef Convex_hull_traits_3<R, Has_filtered_predicates_tag>  Self;
+  typedef Convex_hull_traits_3<R, Polyhedron, Has_filtered_predicates_tag>  Self;
   typedef typename R::Point_3                    Point_3;
   typedef typename R::Segment_3                  Segment_3;
   typedef typename R::Triangle_3                 Triangle_3;
   typedef Point_triple<R>                        Plane_3;
   typedef typename R::Vector_3                   Vector_3;
 
-  typedef CGAL::Polyhedron_3<R>                  Polyhedron_3;
+  typedef Polyhedron                             Polyhedron_3;
 
   typedef typename R::Construct_segment_3        Construct_segment_3;
   typedef typename R::Construct_ray_3            Construct_ray_3;