issue with bootstrap_form (wrong number of arguments (4 for 5))

gistfile1.haml

= bootstrap_form_for(@item, html: { class: 'form-horizontal' }, help: :block) do |f|
  = f.alert_message "Please fix the errors below."
  = f.text_field :name
  = f.text_area :description
  = f.number_field :type
  = f.number_field :condition
  = f.actions do
    = f.primary 'Create My Account', disable_with: 'Saving...'