Victorian firefighters will be the first in the country to fight bushfires at night using firebombing aircraft.
The Civil Aviation Safety Authority has given Victoria's emergency services the green light to use two helicopters at night during the 2018-19 fire season, following a successful trial in February.
Using infrared systems and night-vision goggles, one of the two helicopters used in the trial was able to reach open water, fill up and then drop water onto controlled fires.
The second also conducted a similar test, but is yet to be assessed by the aviation authority.
"The ability to fight fires at night is a game-changer and this is a fantastic outcome," Emergency Management Commissioner Craig Lapsley said in a statement on Tuesday.
"It is a key milestone in an ongoing trial that Victoria has been undertaking with both operators to develop capability to attack wildfires in the late afternoon and into the night using night-vision goggles."
The approvals mean the state will now need to develop policies and procedures to ensure night fire operations can be undertaken safely in real fire situations.
"We'll continue to test into the next summer exactly what conditions and processes are required for night operations to be undertaken safely using the helicopters that have been approved," Mr Lapsley said.
Mr Lapsley said the state was working on the project on behalf of all other states and territories.