--- a/runtime/PLCObject.py	Mon Oct 28 16:06:50 2024 +0100
+++ b/runtime/PLCObject.py	Fri Nov 08 11:34:00 2024 +0100
@@ -829,9 +829,9 @@
         """ Dispatch argument to registered service """
         return self.extended_calls[method](argument)
 
-    def RegisterExtendedCall(method, callback):
+    def RegisterExtendedCall(self, method, callback):
         self.extended_calls[method] = callback
 
-    def UnregisterExtendedCall(method):
+    def UnregisterExtendedCall(self, method):
         del self.extended_calls[method]