diff --git a/include/boost/range/concepts.hpp b/include/boost/range/concepts.hpp
index 4ba7242..f6f9f41 100644
--- a/include/boost/range/concepts.hpp
+++ b/include/boost/range/concepts.hpp
@@ -252,7 +252,7 @@ namespace boost {
                  n = i - j;
              }
          private:
-             BOOST_DEDUCED_TYPENAME RandomAccessIteratorConcept<Iterator>::difference_type n;
+             BOOST_DEDUCED_TYPENAME BidirectionalIteratorConcept<Iterator>::difference_type n;
              Iterator i;
              Iterator j;
  #endif