diff --git a/tools/python/apixml2python/handwritten_definitions.mustache b/tools/python/apixml2python/handwritten_definitions.mustache
index dd19be207..73baddea6 100644
--- a/tools/python/apixml2python/handwritten_definitions.mustache
+++ b/tools/python/apixml2python/handwritten_definitions.mustache
@@ -197,9 +197,11 @@ static PyObject * pylinphone_Core_class_method_new_with_config(PyObject *cls, Py
 
 static void pylinphone_ChatRoom_callback_chat_message_state_changed(LinphoneChatMessage *msg, LinphoneChatMessageState state, void *ud) {
 	PyGILState_STATE pygil_state;
-	PyObject * pycm = NULL;
-	PyObject * func = NULL;
-	pylinphone_ChatRoomObject *pycr = (pylinphone_ChatRoomObject *)ud;
+	PyObject *pycm = NULL;
+	PyObject *func = NULL;
+	PyObject *_dict = (PyObject *)ud;
+	PyObject *_cb = PyDict_GetItemString(_dict, "callback");
+	PyObject *_ud = PyDict_GetItemString(_dict, "user_data");
 
 	pygil_state = PyGILState_Ensure();
 	pycm = linphone_chat_message_get_user_data(msg);
@@ -207,8 +209,8 @@ static void pylinphone_ChatRoom_callback_chat_message_state_changed(LinphoneChat
 		pycm = pylinphone_ChatMessage_new_from_native_ptr(&pylinphone_ChatMessageType, msg);
 	}
 	pylinphone_trace(1, "[PYLINPHONE] >>> %s(%p, %p [%p], %d, %p)", __FUNCTION__, pycm, msg, state, ud);
-	if ((pycr->send_message_cb != NULL) && PyCallable_Check(pycr->send_message_cb)) {
-		if (PyEval_CallObject(pycr->send_message_cb, Py_BuildValue("OiO", pycm, state, pycr->send_message_ud)) == NULL) {
+	if ((_cb != NULL) && PyCallable_Check(_cb)) {
+		if (PyEval_CallObject(_cb, Py_BuildValue("OiO", pycm, state, _ud)) == NULL) {
 			PyErr_Print();
 		}
 	}
@@ -218,6 +220,7 @@ static void pylinphone_ChatRoom_callback_chat_message_state_changed(LinphoneChat
 
 static PyObject * pylinphone_ChatRoom_instance_method_send_message2(PyObject *self, PyObject *args) {
 	PyObject *_chat_message;
+	PyObject *_dict;
 	PyObject *_cb;
 	PyObject *_ud;
 	LinphoneChatMessage * _chat_message_native_ptr;
@@ -234,18 +237,19 @@ static PyObject * pylinphone_ChatRoom_instance_method_send_message2(PyObject *se
 		PyErr_SetString(PyExc_TypeError, "The msg argument must be a linphone.ChatMessage");
 		return NULL;
 	}
-	if (!PyCallable_Check(_cb)) {
+	if ((_cb != Py_None) && !PyCallable_Check(_cb)) {
 		PyErr_SetString(PyExc_TypeError, "The status_cb argument must be a callable");
 		return NULL;
 	}
 	if ((_chat_message_native_ptr = pylinphone_ChatMessage_get_native_ptr(_chat_message)) == NULL) {
 		return NULL;
 	}
+	_dict = PyDict_New();
+	PyDict_SetItemString(_dict, "callback", _cb);
+	PyDict_SetItemString(_dict, "user_data", _ud);
 
 	pylinphone_trace(1, "[PYLINPHONE] >>> %s(%p [%p], %p [%p], %p, %p)", __FUNCTION__, self, native_ptr, _chat_message, _chat_message_native_ptr, _cb, _ud);
-	((pylinphone_ChatRoomObject *)self)->send_message_cb = _cb;
-	((pylinphone_ChatRoomObject *)self)->send_message_ud = _ud;
-	linphone_chat_room_send_message2(native_ptr, _chat_message_native_ptr, pylinphone_ChatRoom_callback_chat_message_state_changed, self);
+	linphone_chat_room_send_message2(native_ptr, _chat_message_native_ptr, pylinphone_ChatRoom_callback_chat_message_state_changed, _dict);
 	pylinphone_dispatch_messages();
 
 	pylinphone_trace(-1, "[PYLINPHONE] <<< %s -> None", __FUNCTION__);