1 files changed, 3 insertions, 0 deletions
diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index f8c7ffdb92..724f9d13a0 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -24,6 +24,8 @@ __version__ = "2.58"
 
 import binascii, errno, random, re, socket, subprocess, sys, time, calendar
 from datetime import datetime, timezone, timedelta
+from io import DEFAULT_BUFFER_SIZE
+
 try:
     import ssl
     HAVE_SSL = True
@@ -1244,6 +1246,7 @@ class IMAP4_stream(IMAP4):
         self.sock = None
         self.file = None
         self.process = subprocess.Popen(self.command,
+            bufsize=DEFAULT_BUFFER_SIZE,
             stdin=subprocess.PIPE, stdout=subprocess.PIPE,
             shell=True, close_fds=True)
         self.writefile = self.process.stdin