diff --git a/Kernel_23/include/CGAL/Bbox.h b/Kernel_23/include/CGAL/Bbox.h
index ec7b35b4314..b0fd9df0647 100644
--- a/Kernel_23/include/CGAL/Bbox.h
+++ b/Kernel_23/include/CGAL/Bbox.h
@@ -127,8 +127,8 @@ template <typename Di, typename T>
 class Bbox;
 
 // A fixed D-dimensional axis aligned box
-template<unsigned int N, typename T>
-class Bbox<Dimension_tag<N>> : public Impl::Bbox<std::array<T, N>, Bbox<N,T>>
+template<int N, typename T>
+class Bbox<Dimension_tag<N>, T> : public Impl::Bbox<std::array<T, N>, Bbox<Dimension_tag<N>,T>>
 {
     enum { D = N };
 public:
@@ -141,7 +141,7 @@ public:
 
 // A dynamic D-dimensional axis aligned box
 template<typename T>
-class Bbox<Dynamic_dimension_tag,T> : public Impl::Bbox<std::vector<T>, Bbox<0,T>>
+class Bbox<Dynamic_dimension_tag,T> : public Impl::Bbox<std::vector<T>, Bbox<Dynamic_dimension_tag,T>>
 {
 public:
     inline int dimension() const { return this->min_values.size(); }