diff --git a/offlineimap/imapserver.py b/offlineimap/imapserver.py
index e2916a4..067d04d 100644
--- a/offlineimap/imapserver.py
+++ b/offlineimap/imapserver.py
@@ -778,7 +778,7 @@ class IdleThread:
             self.thread = Thread(target=self.noop)
         else:
             self.thread = Thread(target=self.__idle)
-        self.thread.setDaemon(1)
+        self.thread.setDaemon(True)
 
     def start(self):
         self.thread.start()
diff --git a/offlineimap/repository/IMAP.py b/offlineimap/repository/IMAP.py
index 68f1800..679af68 100644
--- a/offlineimap/repository/IMAP.py
+++ b/offlineimap/repository/IMAP.py
@@ -60,7 +60,7 @@ class IMAPRepository(BaseRepository):
         self.kathread = ExitNotifyThread(target=self.imapserver.keepalive,
                                          name="Keep alive " + self.getname(),
                                          args=(keepalivetime, self.kaevent))
-        self.kathread.setDaemon(1)
+        self.kathread.setDaemon(True)
         self.kathread.start()
 
     def stopkeepalive(self):