diff --git a/railties/test/application/middleware_test.rb b/railties/test/application/middleware_test.rb
index d88bd05a74eac831ac77e1bf220c01865514f981..44dd0bc8e4475750a8a9ce3af6a9e41361a67ace 100644
--- a/railties/test/application/middleware_test.rb
+++ b/railties/test/application/middleware_test.rb
@@ -116,7 +116,7 @@ def app
 
     test "identity map is inserted" do
       boot!
-      assert_equal "ActiveRecord::IdentityMap::Middleware", middleware[9]
+      assert middleware.include?("ActiveRecord::IdentityMap::Middleware")
     end
 
     test "insert middleware before" do