diff --git a/include/boost/fusion/container/map/detail/map_impl.hpp b/include/boost/fusion/container/map/detail/map_impl.hpp
index cea25496..70491aa5 100644
--- a/include/boost/fusion/container/map/detail/map_impl.hpp
+++ b/include/boost/fusion/container/map/detail/map_impl.hpp
@@ -113,8 +113,8 @@ namespace boost { namespace fusion { namespace detail
         value_type get_val(mpl::identity<key_type>) const;
         pair_type get_val(mpl::int_<index>) const;
 
-        key_type get_key(mpl::int_<index>);
-        key_type get_key(mpl::int_<index>) const;
+        mpl::identity<key_type> get_key(mpl::int_<index>);
+        mpl::identity<key_type> get_key(mpl::int_<index>) const;
 
         typename cref_result<value_type>::type
         get(mpl::identity<key_type>) const
diff --git a/include/boost/fusion/container/map/map_iterator.hpp b/include/boost/fusion/container/map/map_iterator.hpp
index a4ad80f0..d6c1b106 100644
--- a/include/boost/fusion/container/map/map_iterator.hpp
+++ b/include/boost/fusion/container/map/map_iterator.hpp
@@ -54,9 +54,8 @@ namespace boost { namespace fusion
         {
             typedef typename Iterator::sequence sequence;
             typedef typename Iterator::index index;
-            typedef
-                decltype(std::declval<sequence>().get_key(index()))
-            type;
+            typedef decltype(std::declval<sequence>().get_key(index())) key_identity_type;
+            typedef typename key_identity_type::type type;
         };
 
         template<typename Iterator>