Rails AR. validate one field, with 4 validators & 2 condition block

    validates :inn,
              presence: { if: -> { user.is_a?(Client) } },
              inn: { if: -> { user.is_a?(Client) } },
              uniqueness: { if: -> { user.is_a?(Client) } },
              absence: { if: -> { user.is_a?(Department) } }

How would you refactor this?