diff --git a/telegram/ext/updater.py b/telegram/ext/updater.py
index 7fb19c569..420763e87 100644
--- a/telegram/ext/updater.py
+++ b/telegram/ext/updater.py
@@ -382,6 +382,7 @@ class Updater(object):
         for i, thr in enumerate(threads):
             self.logger.debug('Waiting for async thread {0}/{1} to end'.format(i + 1, total))
             thr.join()
+            dispatcher.ASYNC_THREADS.remove(thr)
             self.logger.debug('async thread {0}/{1} has ended'.format(i + 1, total))
 
     def _join_threads(self):