diff --git a/include/boost/tuple/tuple.hpp b/include/boost/tuple/tuple.hpp
index 39b0e13..4e34b6c 100644
--- a/include/boost/tuple/tuple.hpp
+++ b/include/boost/tuple/tuple.hpp
@@ -79,28 +79,31 @@ namespace std
 // std::tuple_size
 
 template<class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10>
-    struct tuple_size< boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >:
-        boost::tuples::length< boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >
+    class tuple_size< boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >:
+        public boost::tuples::length< boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >
 {
 };
 
-template<class H, class T> struct tuple_size< boost::tuples::cons<H, T> >: boost::tuples::length< boost::tuples::cons<H, T> >
+template<class H, class T> class tuple_size< boost::tuples::cons<H, T> >:
+    public boost::tuples::length< boost::tuples::cons<H, T> >
 {
 };
 
-template<> struct tuple_size< boost::tuples::null_type >: boost::tuples::length< boost::tuples::null_type >
+template<> class tuple_size< boost::tuples::null_type >:
+    public boost::tuples::length< boost::tuples::null_type >
 {
 };
 
 // std::tuple_element
 
 template<std::size_t I, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10>
-    struct tuple_element< I, boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >:
-        boost::tuples::element< I, boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >
+    class tuple_element< I, boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >:
+        public boost::tuples::element< I, boost::tuples::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> >
 {
 };
 
-template<std::size_t I, class H, class T> struct tuple_element< I, boost::tuples::cons<H, T> >: boost::tuples::element< I, boost::tuples::cons<H, T> >
+template<std::size_t I, class H, class T> class tuple_element< I, boost::tuples::cons<H, T> >:
+    public boost::tuples::element< I, boost::tuples::cons<H, T> >
 {
 };