diff --git a/concept_check.htm b/concept_check.htm
index 9ddcf8d..1dd72c2 100644
--- a/concept_check.htm
+++ b/concept_check.htm
@@ -250,7 +250,7 @@ bad_error_eg.cpp:8:   instantiated from here
 boost/concept_check.hpp: In destructor ‘boost::LessThanComparable<TT>::~
   LessThanComparable() [with TT = std::complex<float>]’:
 boost/concept/detail/general.hpp:29:   instantiated from ‘static void boost::
-  concept::requirement<Model>::failed() [with Model = boost::
+  concepts::requirement<Model>::failed() [with Model = boost::
   LessThanComparable<std::complex<float> >]’
 boost/concept/requires.hpp:30:   instantiated from ‘boost::_requires_<void
   (*)(boost::LessThanComparable<std::complex<float> >)>’
diff --git a/include/boost/concept/detail/backward_compatibility.hpp b/include/boost/concept/detail/backward_compatibility.hpp
new file mode 100644
index 0000000..88d5921
--- /dev/null
+++ b/include/boost/concept/detail/backward_compatibility.hpp
@@ -0,0 +1,16 @@
+// Copyright David Abrahams 2009. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_CONCEPT_BACKWARD_COMPATIBILITY_DWA200968_HPP
+# define BOOST_CONCEPT_BACKWARD_COMPATIBILITY_DWA200968_HPP
+
+namespace boost
+{
+  namespace concepts {}
+
+# if !defined(BOOST_NO_CONCEPTS) && !defined(BOOST_CONCEPT_NO_BACKWARD_KEYWORD)
+  namespace concept = concepts;
+# endif 
+} // namespace boost::concept
+
+#endif // BOOST_CONCEPT_BACKWARD_COMPATIBILITY_DWA200968_HPP
diff --git a/include/boost/concept/detail/borland.hpp b/include/boost/concept/detail/borland.hpp
old mode 100755
new mode 100644
index 59fec55..300d5d4
--- a/include/boost/concept/detail/borland.hpp
+++ b/include/boost/concept/detail/borland.hpp
@@ -5,8 +5,9 @@
 # define BOOST_CONCEPT_DETAIL_BORLAND_DWA2006429_HPP
 
 # include <boost/preprocessor/cat.hpp>
+# include <boost/concept/detail/backward_compatibility.hpp>
 
-namespace boost { namespace concept {
+namespace boost { namespace concepts {
 
 template <class ModelFnPtr>
 struct require;
@@ -21,7 +22,7 @@ struct require<void(*)(Model)>
   enum                                                  \
   {                                                     \
       BOOST_PP_CAT(boost_concept_check,__LINE__) =      \
-      boost::concept::require<ModelFnPtr>::instantiate  \
+      boost::concepts::require<ModelFnPtr>::instantiate  \
   }
 
 }} // namespace boost::concept
diff --git a/include/boost/concept/detail/general.hpp b/include/boost/concept/detail/general.hpp
index 79ecbe0..e3014c1 100644
--- a/include/boost/concept/detail/general.hpp
+++ b/include/boost/concept/detail/general.hpp
@@ -5,6 +5,7 @@
 # define BOOST_CONCEPT_DETAIL_GENERAL_DWA2006429_HPP
 
 # include <boost/preprocessor/cat.hpp>
+# include <boost/concept/detail/backward_compatibility.hpp>
 
 # ifdef BOOST_OLD_CONCEPT_SUPPORT
 #  include <boost/concept/detail/has_constraints.hpp>
@@ -13,7 +14,7 @@
 
 // This implementation works on Comeau and GCC, all the way back to
 // 2.95
-namespace boost { namespace concept {
+namespace boost { namespace concepts {
 
 template <class ModelFn>
 struct requirement_;
@@ -48,7 +49,7 @@ struct constraint
 template <class Model>
 struct requirement_<void(*)(Model)>
   : mpl::if_<
-        concept::not_satisfied<Model>
+        concepts::not_satisfied<Model>
       , constraint<Model>
       , requirement<failed ************ Model::************>
     >::type
@@ -65,8 +66,8 @@ struct requirement_<void(*)(Model)>
 # endif
 
 #  define BOOST_CONCEPT_ASSERT_FN( ModelFnPtr )             \
-    typedef ::boost::concept::detail::instantiate<          \
-    &::boost::concept::requirement_<ModelFnPtr>::failed>    \
+    typedef ::boost::concepts::detail::instantiate<          \
+    &::boost::concepts::requirement_<ModelFnPtr>::failed>    \
       BOOST_PP_CAT(boost_concept_check,__LINE__)
 
 }}
diff --git a/include/boost/concept/detail/has_constraints.hpp b/include/boost/concept/detail/has_constraints.hpp
old mode 100755
new mode 100644
index 3112b55..7a33813
--- a/include/boost/concept/detail/has_constraints.hpp
+++ b/include/boost/concept/detail/has_constraints.hpp
@@ -6,7 +6,9 @@
 
 # include <boost/mpl/bool.hpp>
 # include <boost/detail/workaround.hpp>
-namespace boost { namespace concept {
+# include <boost/concept/detail/backward_compatibility.hpp>
+
+namespace boost { namespace concepts {
 
 namespace detail
 { 
@@ -43,6 +45,6 @@ struct not_satisfied
     typedef mpl::bool_<value> type;
 };
 
-}} // namespace boost::concept::detail
+}} // namespace boost::concepts::detail
 
 #endif // BOOST_CONCEPT_DETAIL_HAS_CONSTRAINTS_DWA2006429_HPP
diff --git a/include/boost/concept/detail/msvc.hpp b/include/boost/concept/detail/msvc.hpp
index d71d91b..9fbd250 100644
--- a/include/boost/concept/detail/msvc.hpp
+++ b/include/boost/concept/detail/msvc.hpp
@@ -5,6 +5,7 @@
 # define BOOST_CONCEPT_CHECK_MSVC_DWA2006429_HPP
 
 # include <boost/preprocessor/cat.hpp>
+# include <boost/concept/detail/backward_compatibility.hpp>
 
 # ifdef BOOST_OLD_CONCEPT_SUPPORT
 #  include <boost/concept/detail/has_constraints.hpp>
@@ -12,7 +13,7 @@
 # endif
 
 
-namespace boost { namespace concept {
+namespace boost { namespace concepts {
 
 
 template <class Model>
@@ -91,7 +92,7 @@ struct require<void(*)(Model)>
 enum                                                \
 {                                                   \
     BOOST_PP_CAT(boost_concept_check,__LINE__) =    \
-    sizeof(::boost::concept::require<ModelFnPtr>)    \
+    sizeof(::boost::concepts::require<ModelFnPtr>)    \
 }
   
 # else // Not vc-7.1
@@ -104,7 +105,7 @@ require_(void(*)(Model));
 enum                                                    \
 {                                                       \
     BOOST_PP_CAT(boost_concept_check,__LINE__) =        \
-      sizeof(::boost::concept::require_((ModelFnPtr)0)) \
+      sizeof(::boost::concepts::require_((ModelFnPtr)0)) \
 }
   
 # endif
diff --git a/include/boost/concept/usage.hpp b/include/boost/concept/usage.hpp
old mode 100755
new mode 100644
index 9af8ca3..5eee493
--- a/include/boost/concept/usage.hpp
+++ b/include/boost/concept/usage.hpp
@@ -6,8 +6,9 @@
 
 # include <boost/concept/assert.hpp>
 # include <boost/detail/workaround.hpp>
+# include <boost/concept/detail/backward_compatibility.hpp>
 
-namespace boost { namespace concept { 
+namespace boost { namespace concepts { 
 
 # if BOOST_WORKAROUND(__GNUC__, == 2)
 
@@ -25,13 +26,13 @@ struct usage_requirements
 
 #   define BOOST_CONCEPT_USAGE(model)                                    \
       model(); /* at least 2.96 and 3.4.3 both need this :( */           \
-      BOOST_CONCEPT_ASSERT((boost::concept::usage_requirements<model>)); \
+      BOOST_CONCEPT_ASSERT((boost::concepts::usage_requirements<model>)); \
       ~model()
 
 #  else
 
 #   define BOOST_CONCEPT_USAGE(model)                                    \
-      BOOST_CONCEPT_ASSERT((boost::concept::usage_requirements<model>)); \
+      BOOST_CONCEPT_ASSERT((boost::concepts::usage_requirements<model>)); \
       ~model()
 
 #  endif