diff --git a/include/ndnboost/preprocessor/array/elem.hpp b/include/ndnboost/preprocessor/array/elem.hpp
index 22596e2..a6bba6c 100644
--- a/include/ndnboost/preprocessor/array/elem.hpp
+++ b/include/ndnboost/preprocessor/array/elem.hpp
@@ -9,21 +9,21 @@
 #
 # /* See http://www.boost.org for most recent version. */
 #
-# ifndef BOOST_PREPROCESSOR_ARRAY_ELEM_HPP
-# define BOOST_PREPROCESSOR_ARRAY_ELEM_HPP
+# ifndef NDNBOOST_PREPROCESSOR_ARRAY_ELEM_HPP
+# define NDNBOOST_PREPROCESSOR_ARRAY_ELEM_HPP
 #
 # include <ndnboost/preprocessor/array/data.hpp>
 # include <ndnboost/preprocessor/array/size.hpp>
 # include <ndnboost/preprocessor/config/config.hpp>
 # include <ndnboost/preprocessor/tuple/elem.hpp>
 #
-# /* BOOST_PP_ARRAY_ELEM */
+# /* NDNBOOST_PP_ARRAY_ELEM */
 #
-# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
-#    define BOOST_PP_ARRAY_ELEM(i, array) BOOST_PP_TUPLE_ELEM(BOOST_PP_ARRAY_SIZE(array), i, BOOST_PP_ARRAY_DATA(array))
+# if ~NDNBOOST_PP_CONFIG_FLAGS() & NDNBOOST_PP_CONFIG_EDG()
+#    define NDNBOOST_PP_ARRAY_ELEM(i, array) NDNBOOST_PP_TUPLE_ELEM(NDNBOOST_PP_ARRAY_SIZE(array), i, NDNBOOST_PP_ARRAY_DATA(array))
 # else
-#    define BOOST_PP_ARRAY_ELEM(i, array) BOOST_PP_ARRAY_ELEM_I(i, array)
-#    define BOOST_PP_ARRAY_ELEM_I(i, array) BOOST_PP_TUPLE_ELEM(BOOST_PP_ARRAY_SIZE(array), i, BOOST_PP_ARRAY_DATA(array))
+#    define NDNBOOST_PP_ARRAY_ELEM(i, array) NDNBOOST_PP_ARRAY_ELEM_I(i, array)
+#    define NDNBOOST_PP_ARRAY_ELEM_I(i, array) NDNBOOST_PP_TUPLE_ELEM(NDNBOOST_PP_ARRAY_SIZE(array), i, NDNBOOST_PP_ARRAY_DATA(array))
 # endif
 #
 # endif