The usual
diff --git a/Lib/dos-8x3/socketse.py b/Lib/dos-8x3/socketse.py
index 64a86d1..cf8a365 100755
--- a/Lib/dos-8x3/socketse.py
+++ b/Lib/dos-8x3/socketse.py
@@ -396,6 +396,8 @@
 
     def finish(self):
         self.wfile.flush()
+        self.wfile.close()
+        self.rfile.close()
 
 
 class DatagramRequestHandler(BaseRequestHandler):