diff --git a/actionpack/lib/action_dispatch/middleware/stack.rb b/actionpack/lib/action_dispatch/middleware/stack.rb
index 852f697d91..a5f651297a 100644
--- a/actionpack/lib/action_dispatch/middleware/stack.rb
+++ b/actionpack/lib/action_dispatch/middleware/stack.rb
@@ -66,10 +66,6 @@ def [](i)
       middlewares[i]
     end
 
-    def include?(item)
-      middlewares.include? item
-    end
-
     def initialize_copy(other)
       self.middlewares = other.middlewares.dup
     end