diff --git a/offlineimap/imaplibutil.py b/offlineimap/imaplibutil.py
index 6492086..c56b634 100644
--- a/offlineimap/imaplibutil.py
+++ b/offlineimap/imaplibutil.py
@@ -284,8 +284,6 @@ class WrappedIMAP4(UsefulIMAPMixIn, IMAP4):
         # imaplib2 uses this to poll()
         self.read_fd = self.sock.fileno()
 
-mustquote = re.compile(r"[^\w!#$%&'+,.:;<=>?^`|~-]")
-
 def Internaldate2epoch(resp):
     """Convert IMAP4 INTERNALDATE to UT.
 
diff --git a/offlineimap/imapserver.py b/offlineimap/imapserver.py
index 6566ad5..28511bb 100644
--- a/offlineimap/imapserver.py
+++ b/offlineimap/imapserver.py
@@ -212,8 +212,6 @@ class IMAPServer:
                     imapobj = imaplibutil.WrappedIMAP4(self.hostname, self.port,
                                                        timeout=socket.getdefaulttimeout())
 
-                imapobj.mustquote = imaplibutil.mustquote
-
                 if not self.tunnel:
                     try:
                         # Try GSSAPI and continue if it fails