diff --git a/keystone/server/flask/application.py b/keystone/server/flask/application.py
index 8cb1e0e689..4aca52ac6f 100644
--- a/keystone/server/flask/application.py
+++ b/keystone/server/flask/application.py
@@ -230,7 +230,7 @@ def application_factory(name='public'):
                                  rtr in ALL_API_ROUTERS]):
         dispatch_map['/v3/%s' % pfx] = legacy_dispatcher
 
-    application = KeystoneDispatcherMiddleware(
-        app,
+    app.wsgi_app = KeystoneDispatcherMiddleware(
+        app.wsgi_app,
         dispatch_map)
-    return application
+    return app
diff --git a/keystone/server/flask/core.py b/keystone/server/flask/core.py
index 4accdf3612..c7ae055e8c 100644
--- a/keystone/server/flask/core.py
+++ b/keystone/server/flask/core.py
@@ -122,10 +122,10 @@ def setup_app_middleware(app):
         # local_conf, this is all a hold-over from paste-ini and pending
         # reworking/removal(s)
         factory_func = loaded.driver.factory({}, **mw.conf)
-        app = factory_func(app)
+        app.wsgi_app = factory_func(app.wsgi_app)
 
     # Apply werkzeug speficic middleware
-    app = fixers.ProxyFix(app)
+    app.wsgi_app = fixers.ProxyFix(app.wsgi_app)
     return app