diff --git a/include/boost/regex/v4/regex_token_iterator.hpp b/include/boost/regex/v4/regex_token_iterator.hpp
index adbb534d..0a3af367 100644
--- a/include/boost/regex/v4/regex_token_iterator.hpp
+++ b/include/boost/regex/v4/regex_token_iterator.hpp
@@ -110,6 +110,7 @@ public:
          result.first = first;
          result.second = end;
          result.matched = (first != end);
+         N = -1;
          return true;
       }
       return false;
diff --git a/include/boost/regex/v4/u32regex_token_iterator.hpp b/include/boost/regex/v4/u32regex_token_iterator.hpp
index 323d0024..ad75d76a 100644
--- a/include/boost/regex/v4/u32regex_token_iterator.hpp
+++ b/include/boost/regex/v4/u32regex_token_iterator.hpp
@@ -107,6 +107,7 @@ public:
          result.first = first;
          result.second = end;
          result.matched = (first != end);
+         N = -1;
          return true;
       }
       return false;