Legislation that would help implement changes to British royal succession laws passed its first reading in New Zealand's Parliament on Tuesday.
The British Parliament is to change the monarchy's 300-year-old laws, which determine who can become King or Queen.
Aside from the United Kingdom, New Zealand is the only Commonwealth country that includes the laws of succession in its domestic laws.
Justice Minister Judith Collins says the changes ensure that the order of succession will no longer be based on gender, allowing an elder daughter to precede a younger son as heir to the throne.
The change will apply to the child of the Duke and Duchess of Cambridge - the Queen's grandson William and his wife Catherine - due to be born in July.
The bill was debated as Parliament has moved into urgency to pass Government legislation on Tuesday afternoon.
Leader of the House Gerry Brownlee told MPs the Government needed to progress 18 bills through their various stages, as there weren't enough sitting days to do so.
Mr Brownlee said he regretted the need to put Parliament into urgency, but that Opposition parties refused to agree to extended hours.
Legislation to be debated also includes the second reading of Family Court Proceedings Reform Bill.