Correct way to load define-auto-insert in major mode?

[Paul Rankin <hello@paulwrankin.com>]

Is it right to autoload this?

    ;;;###autoload
    (with-eval-after-load 'autoinsert
      (define-auto-insert '(my-major-mode . "My major mode skeleton")
        my-major-mode-skeleton))

This is outside the mode definition. I had put this inside the define-derived-mode macro, but it was duplicating the skeleton to auto-insert-alist each time the mode was loaded.