diff --git a/Mac/Demo/example2/InterslipControl-2.py b/Mac/Demo/example2/InterslipControl-2.py
index 661c4a4..4945864 100644
--- a/Mac/Demo/example2/InterslipControl-2.py
+++ b/Mac/Demo/example2/InterslipControl-2.py
@@ -60,7 +60,7 @@
 			if n == 1:
 				return
 				
-	def idle(self):
+	def idle(self, event):
 		"Idle routine - update status"
 		self.main_dialog.updatestatus()