diff --git a/actionpack/lib/action_dispatch/middleware/flash.rb b/actionpack/lib/action_dispatch/middleware/flash.rb
index c482b1c5e723e64de4ca9a59a243d6df734dacc4..014b7bee617767a047dccdb22ab68e5ae6f79e8a 100644
--- a/actionpack/lib/action_dispatch/middleware/flash.rb
+++ b/actionpack/lib/action_dispatch/middleware/flash.rb
@@ -276,7 +276,7 @@ def call(env)
       req = ActionDispatch::Request.new env
       @app.call(env)
     ensure
-      session    = Request::Session.find(req) || {}
+      session    = req.session || {}
       flash_hash = req.flash_hash
 
       if flash_hash && (flash_hash.present? || session.key?('flash'))