diff --git a/include/boost/type_traits/object_traits.hpp b/include/boost/type_traits/object_traits.hpp
index f023774..17290f6 100644
--- a/include/boost/type_traits/object_traits.hpp
+++ b/include/boost/type_traits/object_traits.hpp
@@ -307,6 +307,7 @@ namespace detail{
 template <typename T>
 struct empty_helper_t1 : public T
 {
+   empty_helper_t1();
    int i[256];
 };
 struct empty_helper_t2 { int i[256]; };