# HG changeset patch
# Parent 4f41c5b9433b6b0e971d484bb1e25a15d002b39f
diff --git a/Lib/poplib.py b/Lib/poplib.py
--- a/Lib/poplib.py
+++ b/Lib/poplib.py
@@ -259,6 +259,7 @@ class POP3:
         if self.file is not None:
             self.file.close()
         if self.sock is not None:
+            self.sock.shutdown(socket.SHUT_RDWR)
             self.sock.close()
         self.file = self.sock = None