diff --git a/include/boost/regex/v4/basic_regex_parser.hpp b/include/boost/regex/v4/basic_regex_parser.hpp
index 7c2852fa..dc528a39 100644
--- a/include/boost/regex/v4/basic_regex_parser.hpp
+++ b/include/boost/regex/v4/basic_regex_parser.hpp
@@ -183,7 +183,7 @@ void basic_regex_parser<charT, traits>::parse(const charT* p1, const charT* p2,
    // have had an unexpected ')' :
    if(!result)
    {
-      fail(regex_constants::error_paren, ::boost::BOOST_REGEX_DETAIL_NS::distance(m_base, m_position), "Found a closing ) with no corresponding openening parenthesis.");
+      fail(regex_constants::error_paren, ::boost::BOOST_REGEX_DETAIL_NS::distance(m_base, m_position), "Found a closing ) with no corresponding opening parenthesis.");
       return;
    }
    // if an error has been set then give up now: