diff --git a/trytond/protocols/xmlrpc.py b/trytond/protocols/xmlrpc.py
index 8a57ab960e..eb759406ff 100644
--- a/trytond/protocols/xmlrpc.py
+++ b/trytond/protocols/xmlrpc.py
@@ -138,6 +138,7 @@ class GenericXMLRPCRequestHandler:
 
 
 class SimpleXMLRPCRequestHandler(GZipRequestHandlerMixin,
+        RegisterHandlerMixin,
         GenericXMLRPCRequestHandler,
         SimpleXMLRPCServer.SimpleXMLRPCRequestHandler):
     protocol_version = "HTTP/1.1"