diff --git a/include/boost/fusion/support/detail/is_same_size.hpp b/include/boost/fusion/support/detail/is_same_size.hpp
index b1bf7cde..02d29534 100644
--- a/include/boost/fusion/support/detail/is_same_size.hpp
+++ b/include/boost/fusion/support/detail/is_same_size.hpp
@@ -9,20 +9,19 @@
 
 #include <boost/fusion/support/is_sequence.hpp>
 #include <boost/fusion/sequence/intrinsic/size.hpp>
-#include <boost/core/enable_if.hpp>
 #include <boost/mpl/bool.hpp>
-#include <boost/mpl/equal_to.hpp>
 
 namespace boost { namespace fusion { namespace detail
 {
-    template <typename Sequence1, typename Sequence2, typename = void, typename = void>
+    template <typename Sequence1, typename Sequence2, bool
+            = traits::is_sequence<Sequence1>::value &&
+              traits::is_sequence<Sequence2>::value>
     struct is_same_size : mpl::false_ {};
 
     template <typename Sequence1, typename Sequence2>
-    struct is_same_size<Sequence1, Sequence2,
-                        typename enable_if<traits::is_sequence<Sequence1> >::type,
-                        typename enable_if<traits::is_sequence<Sequence2> >::type>
-        : mpl::equal_to<result_of::size<Sequence1>, result_of::size<Sequence2> >
+    struct is_same_size<Sequence1, Sequence2, true>
+        : mpl::bool_<result_of::size<Sequence1>::value == 
+                     result_of::size<Sequence2>::value>
     {};
 }}}