diff -r 8a0d001136b1 Objects/cobject.c
--- a/Objects/cobject.c	Wed May 06 00:10:34 2009 -0700
+++ b/Objects/cobject.c	Wed May 06 00:45:02 2009 -0700
@@ -9,11 +9,23 @@
 typedef void (*destructor1)(void *);
 typedef void (*destructor2)(void *, void*);
 
+
+static int deprecation_exception(void)
+{
+    return PyErr_WarnEx(PyExc_PendingDeprecationWarning,
+             "The CObject API is deprecated as of Python 3.1.  "
+             "Please convert to using the Capsule API.", 1);
+}
+
 PyObject *
 PyCObject_FromVoidPtr(void *cobj, void (*destr)(void *))
 {
     PyCObject *self;
 
+    if (deprecation_exception()) {
+        return NULL;
+    }
+
     self = PyObject_NEW(PyCObject, &PyCObject_Type);
     if (self == NULL)
         return NULL;
@@ -30,6 +42,10 @@
 {
     PyCObject *self;
 
+    if (deprecation_exception()) {
+        return NULL;
+    }
+
     if (!desc) {
         PyErr_SetString(PyExc_TypeError,
                         "PyCObject_FromVoidPtrAndDesc called with null"