diff --git a/Lib/SocketServer.py b/Lib/SocketServer.py
index 2c15e9370bb..8e605081691 100644
--- a/Lib/SocketServer.py
+++ b/Lib/SocketServer.py
@@ -570,7 +570,7 @@ def setup(self):
         import StringIO
         self.packet, self.socket = self.request
         self.rfile = StringIO.StringIO(self.packet)
-        self.wfile = StringIO.StringIO(self.packet)
+        self.wfile = StringIO.StringIO()
 
     def finish(self):
         self.socket.sendto(self.wfile.getvalue(), self.client_address)