diff --git a/include/boost/archive/detail/polymorphic_iarchive_impl.hpp b/include/boost/archive/detail/polymorphic_iarchive_impl.hpp
index 14a8fbd6..26f526d9 100644
--- a/include/boost/archive/detail/polymorphic_iarchive_impl.hpp
+++ b/include/boost/archive/detail/polymorphic_iarchive_impl.hpp
@@ -174,6 +174,10 @@ private:
                 ArchiveImplementation::insert_basic_helper(eti, sph);
         }
 public:
+    // this can't be inheriteded because they appear in mulitple
+    // parents
+    typedef mpl::bool_<true> is_loading;
+    typedef mpl::bool_<false> is_saving;
     // the >> operator
     template<class T>
     polymorphic_iarchive & operator>>(T & t){
diff --git a/include/boost/archive/detail/polymorphic_oarchive_impl.hpp b/include/boost/archive/detail/polymorphic_oarchive_impl.hpp
index c42fba24..13007249 100644
--- a/include/boost/archive/detail/polymorphic_oarchive_impl.hpp
+++ b/include/boost/archive/detail/polymorphic_oarchive_impl.hpp
@@ -164,6 +164,10 @@ private:
                 ArchiveImplementation::insert_basic_helper(eti, sph);
         }
 public:
+    // this can't be inheriteded because they appear in mulitple
+    // parents
+    typedef mpl::bool_<false> is_loading;
+    typedef mpl::bool_<true> is_saving;
     // the << operator
     template<class T>
     polymorphic_oarchive & operator<<(T & t){