diff --git a/railties/test/railties/engine_test.rb b/railties/test/railties/engine_test.rb
index ee01a4d6de54f999ad98b44df2fb8a9b1f567823..0ce11b1f793abdd31b196eccf1ea11dc66afc00c 100644
--- a/railties/test/railties/engine_test.rb
+++ b/railties/test/railties/engine_test.rb
@@ -62,12 +62,14 @@ def initialize(app)
 
       def call(env)
         response = @app.call(env)
-        response[2].upcase!
+        response[2].each { |b| b.upcase! }
         response
       end
     end
 
     test "engine is a rack app and can have his own middleware stack" do
+      add_to_config("config.action_dispatch.show_exceptions = false")
+
       @plugin.write "lib/bukkits.rb", <<-RUBY
         class Bukkits
           class Engine < ::Rails::Engine