diff --git a/include/boost/logic/tribool_io.hpp b/include/boost/logic/tribool_io.hpp
index 0d7af8c..2696dca 100644
--- a/include/boost/logic/tribool_io.hpp
+++ b/include/boost/logic/tribool_io.hpp
@@ -45,7 +45,7 @@ template<>
 inline std::basic_string<char> default_false_name<char>()
 { return "false"; }
 
-#  ifndef BOOST_NO_WCHAR_T
+#  if !defined(BOOST_NO_CWCHAR)
 /**
  * \brief Returns the wide character string L"false".
  *
@@ -76,7 +76,7 @@ template<>
 inline std::basic_string<char> default_true_name<char>()
 { return "true"; }
 
-#  ifndef BOOST_NO_WCHAR_T
+#  if !defined(BOOST_NO_CWCHAR)
 /**
  * \brief Returns the wide character string L"true".
  *
@@ -104,7 +104,7 @@ template<>
 inline std::basic_string<char> get_default_indeterminate_name<char>()
 { return "indeterminate"; }
 
-#ifndef BOOST_NO_WCHAR_T
+#if !defined(BOOST_NO_CWCHAR)
 /// Returns the wide character string L"indeterminate".
 template<>
 inline std::basic_string<wchar_t> get_default_indeterminate_name<wchar_t>()
diff --git a/test/tribool_io_test.cpp b/test/tribool_io_test.cpp
index 84bce90..c2d5021 100644
--- a/test/tribool_io_test.cpp
+++ b/test/tribool_io_test.cpp
@@ -20,6 +20,18 @@ int test_main(int, char*[])
 
   tribool x;
 
+  #if !defined(BOOST_NO_CWCHAR) && !defined(BOOST_NO_STD_WSTRING)
+  std::wostringstream wout;
+  wout << std::boolalpha << tribool(false);
+  BOOST_CHECK(wout.str() == L"false");
+  wout.str(std::wstring());
+  wout << std::boolalpha << tribool(true);
+  BOOST_CHECK(wout.str() == L"true");
+  wout.str(std::wstring());
+  wout << std::boolalpha << tribool(indeterminate);
+  BOOST_CHECK(wout.str() == L"indeterminate");
+  #endif
+
   // Check tribool output
   std::ostringstream out;