diff --git a/include/boost/logic/tribool_io.hpp b/include/boost/logic/tribool_io.hpp
index 19eb944..0e16928 100644
--- a/include/boost/logic/tribool_io.hpp
+++ b/include/boost/logic/tribool_io.hpp
@@ -218,7 +218,7 @@ operator<<(std::basic_ostream<CharT, Traits>& out, tribool x)
 template<typename CharT, typename Traits>
 inline std::basic_ostream<CharT, Traits>&
 operator<<(std::basic_ostream<CharT, Traits>& out, 
-           bool (&)(tribool, detail::indeterminate_t))
+           bool (*)(tribool, detail::indeterminate_t))
 { return out << tribool(indeterminate); } 
 
 /**