A/RES/55/255 votes equal to the number of their member States that are Parties to this Protocol. Such organizations shall not exercise their right to vote if their member States exercise theirs and vice versa. 3. An amendment adopted in accordance with paragraph 1 of this article is subject to ratification, acceptance or approval by States Parties. 4. An amendment adopted in accordance with paragraph 1 of this article shall enter into force in respect of a State Party ninety days after the date of the deposit with the Secretary-General of the United Nations of an instrument of ratification, acceptance or approval of such amendment. 5. When an amendment enters into force, it shall be binding on those States Parties which have expressed their consent to be bound by it. Other States Parties shall still be bound by the provisions of this Protocol and any earlier amendments that they have ratified, accepted or approved. Article 20 Denunciation 1. A State Party may denounce this Protocol by written notification to the Secretary-General of the United Nations. Such denunciation shall become effective one year after the date of receipt of the notification by the Secretary-General. 2. A regional economic integration organization shall cease to be a Party to this Protocol when all of its member States have denounced it. Article 21 Depositary and languages 1. The Secretary-General of the United Nations is designated depositary of this Protocol. 2. The original of this Protocol, of which the Arabic, Chinese, English, French, Russian and Spanish texts are equally authentic, shall be deposited with the Secretary-General of the United Nations. IN WITNESS WHEREOF, the undersigned plenipotentiaries, being duly authorized thereto by their respective Governments, have signed this Protocol. 11