diff --git a/include/boost/fusion/algorithm/auxiliary/copy.hpp b/include/boost/fusion/algorithm/auxiliary/copy.hpp
index fd866468..c69e4bd5 100644
--- a/include/boost/fusion/algorithm/auxiliary/copy.hpp
+++ b/include/boost/fusion/algorithm/auxiliary/copy.hpp
@@ -69,7 +69,7 @@ namespace boost { namespace fusion
     copy(Seq1 const& src, Seq2& dest)
     {
         BOOST_STATIC_ASSERT(
-            result_of::size<Seq1>::value == result_of::size<Seq2>::value);
+            result_of::size<Seq1>::value <= result_of::size<Seq2>::value);
 
         detail::sequence_copy<
             Seq1 const, Seq2>::
diff --git a/include/boost/fusion/algorithm/auxiliary/move.hpp b/include/boost/fusion/algorithm/auxiliary/move.hpp
index 6ed968da..68422da9 100644
--- a/include/boost/fusion/algorithm/auxiliary/move.hpp
+++ b/include/boost/fusion/algorithm/auxiliary/move.hpp
@@ -69,7 +69,7 @@ namespace boost { namespace fusion
     move(Seq1&& src, Seq2& dest)
     {
         BOOST_STATIC_ASSERT(
-            result_of::size<Seq1>::value == result_of::size<Seq2>::value);
+            result_of::size<Seq1>::value <= result_of::size<Seq2>::value);
 
         detail::sequence_move<
             Seq1, Seq2>::