diff --git a/include/boost/mpl/map/aux_/at_impl.hpp b/include/boost/mpl/map/aux_/at_impl.hpp
index ae5d3e3..45f83d0 100644
--- a/include/boost/mpl/map/aux_/at_impl.hpp
+++ b/include/boost/mpl/map/aux_/at_impl.hpp
@@ -1,6 +1,6 @@
 
-#ifndef BOOST_MPL_SET_AUX_AT_IMPL_HPP_INCLUDED
-#define BOOST_MPL_SET_AUX_AT_IMPL_HPP_INCLUDED
+#ifndef BOOST_MPL_MAP_AUX_AT_IMPL_HPP_INCLUDED
+#define BOOST_MPL_MAP_AUX_AT_IMPL_HPP_INCLUDED
 
 // Copyright Aleksey Gurtovoy 2003-2004
 // Copyright David Abrahams 2003-2004