--- a/Lib/test/test_asyncore.py
+++ b/Lib/test/test_asyncore.py
@@ -26,6 +26,9 @@
 class dummychannel:
     def __init__(self):
         self.socket = dummysocket()
+
+    def close(self):
+        self.socket.close()
 
 class exitingdummy:
     def __init__(self):