diff --git a/pyptr.h b/pyptr.h
index f6437f4a..81bd7f55 100644
--- a/pyptr.h
+++ b/pyptr.h
@@ -28,13 +28,13 @@ template <class T, class Base>
 struct PyPtrConversions : Base
 {
     inline friend T from_python(PyObject* x, py::Type<const T&>)
-        { return T(x, T::new_ref); }
+        { return T(py::Downcast<T::value_type>(x).get(), T::new_ref); }
 
     inline friend T from_python(PyObject* x, py::Type<T>)
-        { return T(x, T::new_ref); }
+        { return T(py::Downcast<T::value_type>(x).get(), T::new_ref); }
     
     inline friend PyObject* to_python(T x)
-        { return x.release(); }
+        { return as_object(x.release()); }
     
 };
 
@@ -49,6 +49,8 @@ class PyPtr
        boost::dereferenceable<PyPtr<T>, T*> > // supplies op->
 {
 public:
+    typedef T value_type;
+    
 	PyPtr(const PyPtr& rhs)
 		: m_p(rhs.m_p)
 	{