diff --git a/include/boost/io/ios_state.hpp b/include/boost/io/ios_state.hpp
index 2d1625b..c9b4576 100644
--- a/include/boost/io/ios_state.hpp
+++ b/include/boost/io/ios_state.hpp
@@ -10,6 +10,7 @@
 #define BOOST_IO_IOS_STATE_HPP
 
 #include <boost/io_fwd.hpp>  // self include
+#include <boost/detail/workaround.hpp>
 
 #include <ios>        // for std::ios_base, std::basic_ios, etc.
 #ifndef BOOST_NO_STD_LOCALE