Article 18 Accession This Protocol shall remain open for accession by any Member State. Article 19 Amendments 1. Any State Party may propose an amendment to this Protocol. 2. Proposals for amendments to this Protocol shall be made to the Chairperson who shall duly notify all State Parties of the proposed amendments at least three (3) months in advance of the amendments being considered by the Ministerial Committee and the Chairperson shall advise the Chairperson of Summit of the recommendation of the Committee. 3. An amendment to this Protocol shall be adopted by a decision of three-quarters of the State Parties. Article 20 Entry into force This Protocol shall enter into force thirty (30) days after the deposit of the instruments of ratification by two-thirds of the State Parties. Article 21 Depositary 1. The original texts of this Protocol shall be deposited with the Executive Secretary who shall transmit certified copies to all Member States. 2. The Executive Secretary shall register this Protocol with the Secretariat of the United Nations and the Organisation of African Unity. 66