diff --git a/actionpack/lib/action_dispatch/middleware/cookies.rb b/actionpack/lib/action_dispatch/middleware/cookies.rb
index 8c4615c0c1..a4ffd40a66 100644
--- a/actionpack/lib/action_dispatch/middleware/cookies.rb
+++ b/actionpack/lib/action_dispatch/middleware/cookies.rb
@@ -174,7 +174,7 @@ module ActionDispatch
           options = { :value => value }
         end
 
-        value = @cookies[key.to_s] = value
+        @cookies[key.to_s] = value
 
         handle_options(options)