Players will have an additional five seconds between points at next year's Australian Open but time-wasters will have nowhere to hide thanks to the introduction of shot-clocks.
The Grand Slam Board, responsible for the rules at the four majors, confirmed on Tuesday that the Australian Open's request to raise the time from 20 to 25 seconds and strictly enforce it with an electronic shot-clock had been accepted.
The three other slams will also allow 25 seconds, bringing them into line with regular Tour events, but are not currently scheduled to have shot-clocks.
A two-day rules meeting of the Grand Slam Board in London also agreed to limit pre-match warm-ups to five minutes.
Another rule change, which could drastically alter the complexion of majors draws, could also be in place in 2019, with the number of seeds limited to 16 instead of the current 32.
This year's four slams will still have 32 seeds.
The length of time between points has been a cause of consternation in the sport and while increasing the period allowed appears counterintuitive, shot-clocks will take the decision over whether to penalise a slow player out of the umpire's hands.
Currently it is down to the discretion of the official but the inconsistency in enforcing it has caused problems.
The 25-second shot-clock was used in the U.S. Open qualifying event this year and also at the Next Gen ATP Finals in Milan earlier this month.
The Grand Slam Board said in a statement that the serving-time changes had been agreed unanimously.
Speeding up the game and cutting out "dead time" has been a priority for the men's ATP Tour.
ATP chief executive Chris Kermode, who praised the shot-clock innovation in Milan, believes the five-minute pre-match warmup is still too long.
American player Jared Donaldson said before the Milan tournament: "The five-minute warmup maybe is redundant and doesn't necessarily need to take place. Maybe as soon as you walk on court you have five minutes to get ready."
The Australian Open will be more specific than the current grey area, allocating players one minute to walk on and be ready for the umpire's briefing at the net, followed by a five-minute knock-up, plus one minute to prepare for the first point.
Those not ready to play within the permitted time could face fines of $20,000 (£15,117).