diff --git a/test/is_union_test.cpp b/test/is_union_test.cpp
index bd2b4a7..7230c37 100644
--- a/test/is_union_test.cpp
+++ b/test/is_union_test.cpp
@@ -7,47 +7,58 @@
 #include "test.hpp"
 #include "check_integral_constant.hpp"
 #include TYPE_TRAITS(is_union)
+#include <iostream>
 
 TT_TEST_BEGIN(is_union)
 
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<const int>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<volatile int>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int*>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int* const>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int[2]>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int&>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<mf4>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<f1>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<enum_UDT>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<const int>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<volatile int>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int*>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int* const>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int[2]>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<int&>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<mf4>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<f1>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<enum_UDT>::value, false);
 
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<union_UDT>::value, true);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<POD_union_UDT>::value, true);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_union_UDT>::value, true);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_POD_union_UDT>::value, true);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<union_UDT const>::value, true);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<POD_union_UDT volatile>::value, true);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_union_UDT const volatile>::value, true);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_POD_union_UDT const>::value, true);
+#ifdef BOOST_HAS_TYPE_TRAITS_INTRINSICS
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<union_UDT>::value, true);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<POD_union_UDT>::value, true);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_union_UDT>::value, true);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_POD_union_UDT>::value, true);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<union_UDT const>::value, true);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<POD_union_UDT volatile>::value, true);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_union_UDT const volatile>::value, true);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_POD_union_UDT const>::value, true);
+#else
+   std::cout <<
+   "\n<note>\n"
+   "This compiler version does not provide support for is_union on\n"
+   "union types. Such support is not currently required by the\n"
+   "C++ Standard. It will be required to support the upcoming\n"
+   "Standard Library Technical Report.\n"
+   "</note>\n";
+#endif
 
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT const>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT volatile>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_UDT>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<std::iostream>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT const>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT volatile>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<empty_UDT>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<std::iostream>::value, false);
 
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT*>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT[2]>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT&>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<void>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT*>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT[2]>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<UDT&>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<void>::value, false);
 
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<test_abc1>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo0_t>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo1_t>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo2_t>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo3_t>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo4_t>::value, false);
-BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<incomplete_type>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<test_abc1>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo0_t>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo1_t>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo2_t>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo3_t>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<foo4_t>::value, false);
+   BOOST_CHECK_INTEGRAL_CONSTANT(::tt::is_union<incomplete_type>::value, false);
 
 TT_TEST_END