diff --git a/include/boost/intrusive/detail/has_member_function_callable_with.hpp b/include/boost/intrusive/detail/has_member_function_callable_with.hpp
index 33811e3..9be9737 100644
--- a/include/boost/intrusive/detail/has_member_function_callable_with.hpp
+++ b/include/boost/intrusive/detail/has_member_function_callable_with.hpp
@@ -10,7 +10,7 @@
 
 // sample.h
 
-#if !BOOST_PP_IS_ITERATING
+#if !defined(BOOST_PP_IS_ITERATING)
 
    #ifndef BOOST_INTRUSIVE_DETAIL_HAS_MEMBER_FUNCTION_CALLABLE_WITH_DETAILS_INCLUDED
    #define BOOST_INTRUSIVE_DETAIL_HAS_MEMBER_FUNCTION_CALLABLE_WITH_DETAILS_INCLUDED