diff --git a/include/boost/mpl/aux_/na_assert.hpp b/include/boost/mpl/aux_/na_assert.hpp
index 1983c09..aa568d9 100644
--- a/include/boost/mpl/aux_/na_assert.hpp
+++ b/include/boost/mpl/aux_/na_assert.hpp
@@ -22,7 +22,7 @@
     && !BOOST_WORKAROUND(__EDG_VERSION__, <= 243)
 #   include <boost/mpl/assert.hpp>
 #   define BOOST_MPL_AUX_ASSERT_NOT_NA(x) \
-    BOOST_MPL_ASSERT_NOT((boost::mpl::is_na<type>)) \
+    BOOST_MPL_ASSERT_NOT((boost::mpl::is_na<x>)) \
 /**/
 #else
 #   include <boost/static_assert.hpp>