diff --git a/include/boost/mpl/set/aux_/item.hpp b/include/boost/mpl/set/aux_/item.hpp
index 4433572..e90e490 100644
--- a/include/boost/mpl/set/aux_/item.hpp
+++ b/include/boost/mpl/set/aux_/item.hpp
@@ -32,7 +32,7 @@ struct s_item
     typedef s_item<T,Base> item_;
     typedef void_       last_masked_;
     typedef T           item_type_;
-    typedef Base        base;
+    typedef typename Base::item_ base;
     
     typedef typename next< typename Base::size >::type  size;
     typedef typename next< typename Base::order >::type order;
@@ -55,7 +55,7 @@ struct s_mask
     typedef s_mask<T,Base> item_;
     typedef T       last_masked_;
     typedef void_   item_type_;
-    typedef Base    base;
+    typedef typename Base::item_ base;
     typedef typename prior< typename Base::size >::type  size;
 
     BOOST_MPL_AUX_SET_OVERLOAD( aux::yes_tag, IS_MASKED, s_mask, aux::type_wrapper<T>* );
@@ -69,7 +69,7 @@ struct s_unmask
     typedef s_unmask<T,Base> item_;
     typedef void_   last_masked_;
     typedef T       item_type_;
-    typedef Base    base;
+    typedef typename Base::item_ base;
     typedef typename next< typename Base::size >::type  size;
 
     BOOST_MPL_AUX_SET_OVERLOAD( aux::no_tag, IS_MASKED, s_unmask, aux::type_wrapper<T>* );
diff --git a/test/set_c.cpp b/test/set_c.cpp
index 1a6e970..e34d86d 100644
--- a/test/set_c.cpp
+++ b/test/set_c.cpp
@@ -14,6 +14,7 @@
 #include <boost/mpl/set_c.hpp>
 #include <boost/mpl/at.hpp>
 #include <boost/mpl/size.hpp>
+#include <boost/mpl/begin_end.hpp>
 
 #include <boost/mpl/aux_/test.hpp>
 
@@ -59,6 +60,18 @@ MPL_TEST_CASE()
     MPL_ASSERT(( is_same< test::at_c<s1,false>::type, void_ > ));
     MPL_ASSERT(( is_same< test::at_c<s2,true>::type, void_ > ));
 #endif
+
+    typedef begin<s1>::type first1;
+    typedef end<s1>::type last1;
+    MPL_ASSERT_RELATION( (distance<first1, last1>::value), ==, 1 );
+
+    typedef begin<s2>::type first2;
+    typedef end<s2>::type last2;
+    MPL_ASSERT_RELATION( (distance<first2, last2>::value), ==, 1 );
+    
+    typedef begin<s3>::type first3;
+    typedef end<s3>::type last3;
+    MPL_ASSERT_RELATION( (distance<first3, last3>::value), ==, 2 );
 }
 #endif
 
@@ -82,4 +95,12 @@ MPL_TEST_CASE()
     MPL_ASSERT(( is_same< test::at_c<s1,'z'>::type, void_ > ));
     MPL_ASSERT(( is_same< test::at_c<s2,'k'>::type, void_ > ));
 #endif
+    
+    typedef begin<s1>::type first1;
+    typedef end<s1>::type last1;
+    MPL_ASSERT_RELATION( (distance<first1, last1>::value), ==, 1 );
+
+    typedef begin<s2>::type first2;
+    typedef end<s2>::type last2;
+    MPL_ASSERT_RELATION( (distance<first2, last2>::value), ==, 8 );
 }