Maori Party co-leader Te Ururoa Flavell's five children grew up in a Maori-speaking household.
But now the kids have left home the Maori Development Minister often finds himself talking to wife Erana Hond-Flavell in English - particularly after arriving home from a stint at Parliament.
"When I come back from Wellington it's my wife's view that I stay too easily in English," Flavell said. "And it was her challenge that we need to be a bit stronger in trying to maintain a Maori-speaking environment."
Flavell and Erana have now taken a New Year's resolution to talk to each other only in Maori for a year. He said he would also try to avoid English when speaking with other te reo speakers.
"There are a lot of people around, some in my office, who I deal with on a day-to-day basis where we should be conversing in Maori," Flavell said.
"The challenge is for me to try and stay with Maori language as much as possible, understanding of course that in the Parliamentary environment it's not always easy to do that.
"I'm Minister for Maori Development, and I wanted to take a lead role to promote the speaking of the Maori language as much as possible."
Flavell has also asked other Maori speakers to provide him with new words to ensure his vocabulary doesn't become stale. Those are being posted on his Facebook page, and followers are encouraged to use the words in sentences.
According to Census data, between 1996 and 2013 the proportion of Maori able to converse in te reo fell from 25 per cent to 21 per cent.
Flavell said New Zealand's appreciation and use of the Maori language was slowly improving.
The Maori Party had successfully pushed for simultaneous translation during Parliamentary business, and Flavell praised Radio New Zealand reporters for signing off their stories in Maori.