diff --git a/test/functional/attachments_controller_test.rb b/test/functional/attachments_controller_test.rb
index 5800307..1f014cd 100644
--- a/test/functional/attachments_controller_test.rb
+++ b/test/functional/attachments_controller_test.rb
@@ -193,12 +193,12 @@ class AttachmentsControllerTest < ActionController::TestCase
   end
 
   def test_show_text_file_should_send_if_too_big
-    Setting.file_max_size_displayed = 512
-    Attachment.find(4).update_attribute :filesize, 754.kilobyte
-
-    get :show, :id => 4
-    assert_response :success
-    assert_equal 'application/x-ruby', @response.content_type
+    with_settings :file_max_size_displayed => 512 do
+      Attachment.find(4).update_attribute :filesize, 754.kilobyte
+      get :show, :id => 4
+      assert_response :success
+      assert_equal 'application/x-ruby', @response.content_type
+    end
     set_tmp_attachments_directory
   end