diff --git a/src/python.c b/src/python.c
index 6be727e..ccc1c86 100644
--- a/src/python.c
+++ b/src/python.c
@@ -439,7 +439,7 @@ static int cpy_write_callback(const data_set_t *ds, const value_list_t *value_li
                v->values = list;
                v->meta = dict;
                ret = PyObject_CallFunctionObjArgs(c->callback, v, c->data, (void *) 0); /* New reference
-               Py_XDECREF(v);
+               Py_XDECREF(&v->data);
                if (ret == NULL) {
                        cpy_log_exception("write callback");
                } else {
@@ -465,7 +465,7 @@ static int cpy_notification_callback(const notification_t *notification, user_da
                sstrncpy(n->message, notification->message, sizeof(n->message));
                n->severity = notification->severity;
                ret = PyObject_CallFunctionObjArgs(c->callback, n, c->data, (void *) 0); /* New reference
-               Py_XDECREF(n);
+               Py_XDECREF(&n->data);
                if (ret == NULL) {
                        cpy_log_exception("notification callback");
                } else {