diff --git a/include/boost/mpl/vector/aux_/tag.hpp b/include/boost/mpl/vector/aux_/tag.hpp
index 940f490..29a0a3b 100644
--- a/include/boost/mpl/vector/aux_/tag.hpp
+++ b/include/boost/mpl/vector/aux_/tag.hpp
@@ -15,6 +15,7 @@
 // $Revision$
 
 #include <boost/mpl/aux_/config/typeof.hpp>
+#include <boost/mpl/aux_/nttp_decl.hpp>
 
 namespace boost { namespace mpl { namespace aux {
 
@@ -23,7 +24,7 @@ struct v_iter_tag;
 #if defined(BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES)
 struct vector_tag;
 #else
-template< long N > struct vector_tag;
+template< BOOST_MPL_AUX_NTTP_DECL(long, N) > struct vector_tag;
 #endif
 
 }}}