diff --git a/Spatial_sorting/include/CGAL/hilbert_sort.h b/Spatial_sorting/include/CGAL/hilbert_sort.h
index b79431b28d2..3d58550d99f 100644
--- a/Spatial_sorting/include/CGAL/hilbert_sort.h
+++ b/Spatial_sorting/include/CGAL/hilbert_sort.h
@@ -53,7 +53,7 @@ namespace internal {
     template <class RandomAccessIterator, class Policy, class Kernel>
       void hilbert_sort (RandomAccessIterator begin, 
 			 RandomAccessIterator end,
-			 Policy policy,
+			 Policy /*policy*/,
 			 const Kernel &k, typename Kernel::Point_3 *)
     {
         boost::rand48 random;
@@ -65,7 +65,7 @@ namespace internal {
     template <class RandomAccessIterator, class Policy, class Kernel>
       void hilbert_sort (RandomAccessIterator begin,
 			 RandomAccessIterator end,
-			 Policy policy,
+			 Policy /*policy*/,
 			 const Kernel &k, typename Kernel::Point_d *)
     {
         boost::rand48 random;