diff --git a/include/boost/python/object_core.hpp b/include/boost/python/object_core.hpp
index 61857796..209310ff 100644
--- a/include/boost/python/object_core.hpp
+++ b/include/boost/python/object_core.hpp
@@ -422,6 +422,7 @@ inline api::object_base& api::object_base::operator=(api::object_base const& rhs
 
 inline api::object_base::~object_base()
 {
+    assert( Py_REFCNT(m_ptr) > 0 );
     Py_DECREF(m_ptr);
 }
 
diff --git a/include/boost/python/refcount.hpp b/include/boost/python/refcount.hpp
index 5ba5433c..aa6aa5db 100755
--- a/include/boost/python/refcount.hpp
+++ b/include/boost/python/refcount.hpp
@@ -27,12 +27,14 @@ inline T* xincref(T* p)
 template <class T>
 inline void decref(T* p)
 {
+    assert( Py_REFCNT(python::upcast<PyObject>(p)) > 0 );
     Py_DECREF(python::upcast<PyObject>(p));
 }
 
 template <class T>
 inline void xdecref(T* p)
 {
+    assert( !p || Py_REFCNT(python::upcast<PyObject>(p)) > 0 );
     Py_XDECREF(python::upcast<PyObject>(p));
 }