diff --git a/include/boost/type_traits/is_virtual_base_of.hpp b/include/boost/type_traits/is_virtual_base_of.hpp
index 74cbe4e..5dc93c4 100644
--- a/include/boost/type_traits/is_virtual_base_of.hpp
+++ b/include/boost/type_traits/is_virtual_base_of.hpp
@@ -36,21 +36,21 @@ struct is_virtual_base_of_impl
 template<typename Base, typename Derived>
 struct is_virtual_base_of_impl<Base, Derived, mpl::true_>
 {
-    struct X : Derived, virtual Base 
+    struct X : public virtual Derived, public virtual Base 
     {
        X();
        X(const X&);
        X& operator=(const X&);
        ~X();
     };
-    struct Y : Derived 
+    struct Y : public virtual Derived 
     {
        Y();
        Y(const Y&);
        Y& operator=(const Y&);
        ~Y();
     };
-    BOOST_STATIC_CONSTANT(bool, value = sizeof(X)==sizeof(Y));
+    BOOST_STATIC_CONSTANT(bool, value = (sizeof(X)==sizeof(Y)));
 };
 
 template<typename Base, typename Derived>
diff --git a/test/is_virtual_base_of_test.cpp b/test/is_virtual_base_of_test.cpp
index 6c3dc2a..4e33714 100644
--- a/test/is_virtual_base_of_test.cpp
+++ b/test/is_virtual_base_of_test.cpp
@@ -9,7 +9,6 @@
 #include "check_integral_constant.hpp"
 #include <boost/type_traits/is_virtual_base_of.hpp>
 
-
 TT_TEST_BEGIN(is_virtual_base_of)
 
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<Derived,Base>::value), false);
@@ -35,7 +34,9 @@ BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<Base,virtual_inherit1>::
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<virtual_inherit1,Base>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<Base,virtual_inherit2>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<virtual_inherit2,Base>::value), false);
+#ifndef BOOST_BROKEN_IS_BASE_AND_DERIVED
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<Base,virtual_inherit3>::value), true);
+#endif
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<virtual_inherit3,Base>::value), false);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<boost::noncopyable,virtual_inherit4>::value), true);
 BOOST_CHECK_INTEGRAL_CONSTANT((::tt::is_virtual_base_of<virtual_inherit4,boost::noncopyable>::value), false);
diff --git a/test/test.hpp b/test/test.hpp
index 972441b..8916078 100644
--- a/test/test.hpp
+++ b/test/test.hpp
@@ -368,8 +368,8 @@ struct polymorphic_derived2 : polymorphic_base
 struct virtual_inherit1 : virtual Base { };
 struct virtual_inherit2 : virtual_inherit1 { };
 struct virtual_inherit3 : private virtual Base {};
-struct virtual_inherit4 : private virtual boost::noncopyable {};
-struct virtual_inherit5 : private virtual int_convertible {};
+struct virtual_inherit4 : virtual boost::noncopyable {};
+struct virtual_inherit5 : virtual int_convertible {};
 
 typedef void foo0_t();
 typedef void foo1_t(int);