diff --git a/Lib/mimetools.py b/Lib/mimetools.py
index eb0ab713109..d51953908f8 100644
--- a/Lib/mimetools.py
+++ b/Lib/mimetools.py
@@ -112,7 +112,6 @@ def choose_boundary():
     import random
     if _prefix is None:
         import socket
-        import os
         hostid = socket.gethostbyname(socket.gethostname())
         try:
             uid = `os.getuid()`