diff --git a/include/boost/smart_ptr/intrusive_ptr.hpp b/include/boost/smart_ptr/intrusive_ptr.hpp
index 58041da..1e93397 100644
--- a/include/boost/smart_ptr/intrusive_ptr.hpp
+++ b/include/boost/smart_ptr/intrusive_ptr.hpp
@@ -122,6 +122,30 @@ public:
         return *this;
     }
 
+    template<class U> friend class intrusive_ptr;
+
+    template<class U>
+#if !defined( BOOST_SP_NO_SP_CONVERTIBLE )
+
+    intrusive_ptr(intrusive_ptr<U> && rhs, typename boost::detail::sp_enable_if_convertible<U,T>::type = boost::detail::sp_empty())
+
+#else
+
+    intrusive_ptr(intrusive_ptr<U> && rhs)
+
+#endif        
+    : px( rhs.px )
+    {
+        rhs.px = 0;
+    }
+
+    template<class U>
+    intrusive_ptr & operator=(intrusive_ptr<U> && rhs) BOOST_NOEXCEPT
+    {
+        this_type( static_cast< intrusive_ptr<U> && >( rhs ) ).swap(*this);
+        return *this;
+    }
+
 #endif
 
     intrusive_ptr & operator=(intrusive_ptr const & rhs)
diff --git a/test/intrusive_ptr_move_test.cpp b/test/intrusive_ptr_move_test.cpp
index 0e89764..2f2f652 100644
--- a/test/intrusive_ptr_move_test.cpp
+++ b/test/intrusive_ptr_move_test.cpp
@@ -143,6 +143,18 @@ int main()
         BOOST_TEST( N::base::instances == 0 );
     }
 
+    {
+        boost::intrusive_ptr<Y> p( new Y );
+        BOOST_TEST( N::base::instances == 1 );
+
+        boost::intrusive_ptr<X> p2( std::move( p ) );
+        BOOST_TEST( N::base::instances == 1 );
+        BOOST_TEST( p.get() == 0 );
+
+        p2.reset();
+        BOOST_TEST( N::base::instances == 0 );
+    }
+
     {
         boost::intrusive_ptr<X> p( new X );
         BOOST_TEST( N::base::instances == 1 );
@@ -170,6 +182,33 @@ int main()
         BOOST_TEST( N::base::instances == 0 );
     }
 
+    {
+        boost::intrusive_ptr<Y> p( new Y );
+        BOOST_TEST( N::base::instances == 1 );
+
+        boost::intrusive_ptr<X> p2;
+        p2 = std::move( p );
+        BOOST_TEST( N::base::instances == 1 );
+        BOOST_TEST( p.get() == 0 );
+
+        p2.reset();
+        BOOST_TEST( N::base::instances == 0 );
+    }
+
+    {
+        boost::intrusive_ptr<Y> p( new Y );
+        BOOST_TEST( N::base::instances == 1 );
+
+        boost::intrusive_ptr<X> p2( new X );
+        BOOST_TEST( N::base::instances == 2 );
+        p2 = std::move( p );
+        BOOST_TEST( N::base::instances == 1 );
+        BOOST_TEST( p.get() == 0 );
+
+        p2.reset();
+        BOOST_TEST( N::base::instances == 0 );
+    }
+
     return boost::report_errors();
 }