diff --git a/include/boost/regex/config/cstring.hpp b/include/boost/regex/config/cstring.hpp
index 4c607698..316f0b8c 100644
--- a/include/boost/regex/config/cstring.hpp
+++ b/include/boost/regex/config/cstring.hpp
@@ -25,6 +25,9 @@
 
 #include <cstring>
 #include <cctype>
+#ifdef __KCC
+#include <ios>
+#endif
 #include <boost/config.hpp>
 
 namespace std{