Police Association president Chris Cahill said the collective agreement already had a provision that except in cases of emergency, police shouldn't change someone's roster without giving them 14 days notice.
"The problem was there was absolutely no penalty involved in that," Cahill said.
"So police ignored it. To the level that it became incredibly frustrating for staff to organise their lives and at the last minute be told, now we need you to work this roster."
Cahill said the Association had been surprised how many police staff are enduring roster changes as a result of having to attend court at short notice.
"And, in hindsight, this shouldn't be a surprise because we have said for many, many years, that the court needs to tidy up their act on how they manage court.
"This has been something that we've spoken about on behalf of victims for years."
Cahill said he hoped the new system might spur a conversation between police and the Ministry of Justice about better aligning their processes.
The Herald has sought comment from police on the financial impact of the new payment scheme.