diff --git a/include/boost/mp11/detail/mp_plus.hpp b/include/boost/mp11/detail/mp_plus.hpp
index c27e6de..57cf3cc 100644
--- a/include/boost/mp11/detail/mp_plus.hpp
+++ b/include/boost/mp11/detail/mp_plus.hpp
@@ -8,7 +8,7 @@
 //  See accompanying file LICENSE_1_0.txt or copy at
 //  http://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/config.hpp>
+#include <boost/mp11/detail/config.hpp>
 #include <type_traits>
 
 namespace boost
@@ -20,6 +20,16 @@ namespace mp11
 namespace detail
 {
 
+#if defined( BOOST_MP11_HAS_FOLD_EXPRESSIONS )
+
+template<class... T> struct mp_plus_impl
+{
+    static const auto _v = (T::value + ... + 0);
+    using type = std::integral_constant<typename std::remove_const<decltype(_v)>::type, _v>;
+};
+
+#else
+
 template<class... T> struct mp_plus_impl;
 
 template<> struct mp_plus_impl<>
@@ -29,16 +39,18 @@ template<> struct mp_plus_impl<>
 
 template<class T1, class... T> struct mp_plus_impl<T1, T...>
 {
-    static const/*expr*/ auto _v = T1::value + mp_plus_impl<T...>::type::value;
+    static const auto _v = T1::value + mp_plus_impl<T...>::type::value;
     using type = std::integral_constant<typename std::remove_const<decltype(_v)>::type, _v>;
 };
 
 template<class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class... T> struct mp_plus_impl<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T...>
 {
-    static const/*expr*/ auto _v = T1::value + T2::value + T3::value + T4::value + T5::value + T6::value + T7::value + T8::value + T9::value + T10::value + mp_plus_impl<T...>::type::value;
+    static const auto _v = T1::value + T2::value + T3::value + T4::value + T5::value + T6::value + T7::value + T8::value + T9::value + T10::value + mp_plus_impl<T...>::type::value;
     using type = std::integral_constant<typename std::remove_const<decltype(_v)>::type, _v>;
 };
 
+#endif
+
 } // namespace detail
 
 template<class... T> using mp_plus = typename detail::mp_plus_impl<T...>::type;