diff --git a/include/boost/regex/v4/sub_match.hpp b/include/boost/regex/v4/sub_match.hpp
index 10fbb1ce..e67a2f84 100644
--- a/include/boost/regex/v4/sub_match.hpp
+++ b/include/boost/regex/v4/sub_match.hpp
@@ -35,6 +35,8 @@ struct sub_match : public std::pair<BidiIterator, BidiIterator>
    typedef typename re_detail::regex_iterator_traits<BidiIterator>::difference_type  difference_type;
 #endif
    typedef          BidiIterator                                                     iterator_type;
+   typedef          BidiIterator                                                     iterator;
+   typedef          BidiIterator                                                     const_iterator;
 
    bool matched;