diff --git a/include/boost/container/detail/is_pair.hpp b/include/boost/container/detail/is_pair.hpp
index e208a5c..239e36e 100644
--- a/include/boost/container/detail/is_pair.hpp
+++ b/include/boost/container/detail/is_pair.hpp
@@ -25,6 +25,14 @@
 #include <boost/container/detail/workaround.hpp>
 #include <boost/container/detail/std_fwd.hpp>
 
+#if defined(BOOST_MSVC) && (_CPPLIB_VER == 520)
+//MSVC 2010 tuple marker
+namespace std { namespace tr1 { struct _Nil; }}
+#elif defined(BOOST_MSVC) && (_CPPLIB_VER == 540)
+//MSVC 2012 tuple marker
+namespace std { struct _Nil; }
+#endif
+
 namespace boost {
 namespace tuples {
 
diff --git a/include/boost/container/detail/pair.hpp b/include/boost/container/detail/pair.hpp
index 89b7876..1537cf7 100644
--- a/include/boost/container/detail/pair.hpp
+++ b/include/boost/container/detail/pair.hpp
@@ -77,19 +77,7 @@ struct is_tuple_null<boost::tuples::null_type>
    static const bool value = true;
 };
 
-}}}
-
-#if defined(BOOST_MSVC) && (_CPPLIB_VER == 520)
-//MSVC 2010 tuple marker
-namespace std { namespace tr1 { struct _Nil; }}
-#elif defined(BOOST_MSVC) && (_CPPLIB_VER == 540)
-//MSVC 2012 tuple marker
-namespace std { struct _Nil; }
-#endif
-
-
-namespace boost {
-namespace container {
+}  //namespace detail {
 
 #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED