```ruby
module UrlNormalization
  def normalize_url(field_name)
    define_method "#{field_name}=" do |val|
      val = "http://#{val}" if !val.blank? && !(val =~ /^http/)
      write_attribute(field_name, val)
    end
  end
end
```

Call super instead of write_attribute
user
```ruby
module UrlNormalization
  def normalize_url(field_name)
    define_method "#{field_name}=" do |val|
      val = "http://#{val}" if !val.blank? && !(val =~ /^http/)
      super(val)
    end
  end
end
```
assistant