diff --git a/include/boost/mpl/bool_c.hpp b/include/boost/mpl/bool_c.hpp
index 1dae9f8..7c466b6 100644
--- a/include/boost/mpl/bool_c.hpp
+++ b/include/boost/mpl/bool_c.hpp
@@ -34,12 +34,6 @@ template< bool C > struct bool_c
 typedef bool_c<true> true_c;
 typedef bool_c<false> false_c;
 
-namespace v2_1 {
-using mpl::bool_c;
-using mpl::true_c;
-using mpl::false_c;
-}
-
 } // namespace mpl
 } // namespace boost