diff --git a/guides/source/active_record_validations_callbacks.md b/guides/source/active_record_validations_callbacks.md
index 5c27ccbf9e45b98c28d5be9f3fb96af1f3240b0d..0f4140b6500ba8dfe326a83329968e91a9c6c375 100644
--- a/guides/source/active_record_validations_callbacks.md
+++ b/guides/source/active_record_validations_callbacks.md
@@ -953,8 +953,12 @@ Below is a simple example where we change the Rails behavior to always display t
```ruby
ActionView::Base.field_error_proc = Proc.new do |html_tag, instance|
- errors = Array(instance.error_message).join(',')
- %(#{html_tag} #{errors}).html_safe
+ if html_tag =~ /\