How do use emacs-state in certain modes?

Hello. I want to use emacs-state in term-mode and undo-tree-mode. How do I achieve that? I tried: (add-to-list 'evil-emacs-state-modes undo-tree-mode) This didn't work for some reason. So again, What should I do to be in emacs-state in term-mode for exmaple? Thanks for your time and kind concern.