Rails3.2からRails4にバージョンアップしました。独自に作成したmy_resource/base.rbの中でdemodulizeメソッドを呼び出しているですがバージョンアップにより使えなくなりました。

2015/11/20 18:02:16 [INFO] ::   Rendered pogepoge/_select_hoge.html.erb (317.7ms)

2015/11/20 18:02:16 [ERROR] :: ref:[4c1-3992] type:[APPLICATION_ERROR] アプリケーションエラー。, undefined method `demodulize' for #

2015/11/20 18:02:16 [INFO] ::

    /poge/hoge/workspace/version/app/pogeapp/lib/my_resource/base.rb:291:in `demodulized_underscore_name'

    /poge/hoge/workspace/version/app/pogeapp/app/views/pogepoge/_select_hoge.html.erb:55:in `block (5 levels) in _pogepoge__select_hoge_html_erb___2093292265898603831_70005643233100'

    /poge/hoge/workspace/version/app/pogeapp/app/helpers/application_helper.rb:1826:in `show_table_if_exists'

    /poge/hoge/workspace/version/app/pogeapp/app/views/pogepoge/_select_hoge.html.erb:54:in `block (4 levels) in _pogepoge__select_hoge_html_erb___2093292265898603831_70005643233100'

    /poge/hoge/workspace/version/app/pogeapp/app/helpers/application_helper.rb:1638:in `block (3 levels) in widget_box_frame'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:38:in `block in capture'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:200:in `with_output_buffer'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:38:in `capture'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/tag_helper.rb:94:in `content_tag'

    /poge/hoge/workspace/version/app/pogeapp/app/helpers/application_helper.rb:1637:in `block (2 levels) in widget_box_frame'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:38:in `block in capture'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:200:in `with_output_buffer'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:38:in `capture'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/tag_helper.rb:94:in `content_tag'

    /poge/hoge/workspace/version/app/pogeapp/app/helpers/application_helper.rb:1636:in `block in widget_box_frame'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:38:in `block in capture'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:200:in `with_output_buffer'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/capture_helper.rb:38:in `capture'

    /poge/hoge/.rbenv/versions/2.2.3/gemsets/4.0/gems/actionpack-4.0.13/lib/action_view/helpers/tag_helper.rb:94:in `content_tag'

実コードはこんな感じです。
クラス名を取ってきて小文字にしています。demodulizeメソッドが無いと出ています。

def demodulized_underscore_name
    my_class.demodulize.underscore
end

my_classのクラス名をデバックで見てみたらActiveModel::Nameになっていました。
baseやinitializerにrequire 'active_support/inflector/methods'入れてみましたが
動きませんでした。解決方法をご存知でしたら教えていただきたく。