Comment 6 for bug 1942179

diff --git a/routes/middleware.py b/routes/middleware.py
index 649aa25..d06fd70 100644
--- a/routes/middleware.py
+++ b/routes/middleware.py
@@ -3,10 +3,12 @@ import re
 import logging

 from webob import Request
+from eventlet import greenthread

 from routes.base import request_config
 from routes.util import URLGenerator

+
 log = logging.getLogger('routes.middleware')

@@ -155,6 +157,9 @@ class RoutesMiddleware(object):
         # Wrapped in try as in rare cases the attribute will be gone already
         try:
             del self.mapper.environ
+ if self.singleton:
+ cur = greenthread.getcurrent()
+ del config._RequestConfig__shared_state._local__greens[cur]
         except AttributeError:
             pass
         return response