diff --git a/sedbgmux.py b/sedbgmux.py
index 675e35b..470406f 100755
--- a/sedbgmux.py
+++ b/sedbgmux.py
@@ -147,7 +147,8 @@ class SEDbgMuxApp(cmd2.Cmd):
         # Read the messages
         while True:
             f = self.peer.recv()
-
+            if f is None:
+                continue  # No more data in the buffer
             if f['MsgType'] != DbgMuxFrame.MsgType.ConnData:
                 log.warning('Unexpected frame: %s', f)
                 self.peer.send(DbgMuxFrame.MsgType.Ack)