diff --git a/include/boost/mpl/vector/aux_/at.hpp b/include/boost/mpl/vector/aux_/at.hpp
index ce5fe34..e63603d 100644
--- a/include/boost/mpl/vector/aux_/at.hpp
+++ b/include/boost/mpl/vector/aux_/at.hpp
@@ -17,6 +17,7 @@
 #include <boost/mpl/at_fwd.hpp>
 #include <boost/mpl/vector/aux_/tag.hpp>
 #include <boost/mpl/long.hpp>
+#include <boost/mpl/void.hpp>
 #include <boost/mpl/aux_/nttp_decl.hpp>
 #include <boost/mpl/aux_/type_wrapper.hpp>
 #include <boost/mpl/aux_/value_wknd.hpp>
@@ -89,6 +90,15 @@ template< BOOST_MPL_AUX_NTTP_DECL(long, n_) > struct v_at_impl
     template< typename V > struct result_;
 };
 
+// to work around ETI, etc.
+template<> struct v_at_impl<-1>
+{
+    template< typename V > struct result_
+    {
+        typedef void_ type;
+    };
+};
+
 } // namespace aux
 
 template< typename T, BOOST_MPL_AUX_NTTP_DECL(long, n_) >