diff --git a/radicale/auth/imap.py b/radicale/auth/imap.py
index 3fdbaa70..18af91d1 100644
--- a/radicale/auth/imap.py
+++ b/radicale/auth/imap.py
@@ -59,7 +59,10 @@ class Auth(auth.BaseAuth):
                 if self._security == "starttls":
                     connection.starttls(ssl.create_default_context())
             try:
-                connection.login(login, password)
+                connection.authenticate(
+                    "PLAIN",
+                    lambda _: "{0}\x00{0}\x00{1}".format(login, password).encode(),
+                )
             except imaplib.IMAP4.error as e:
                 logger.warning("IMAP authentication failed for user %r: %s", login, e, exc_info=False)
                 return ""