The Howlin' Wolf Bar in Woolongong is offering $1 off espresso martinis for customers who bring along a keep cup.
And while the bar jokes "over four coupe glasses a year get shattered in our bars in espresso martini related incidents", this is not a gimmick.
Luke Symons, co-owner of the bar, told 10 daily the initiative was a way of making their patrons more environmentally conscious while out having a drink.
"The vast majority of keep cups users will get a coffee every morning on their way to work or perhaps even a tea, but we thought, what about on the way home?" he said.
But it's not just about the punters being environmentally conscious, but the bar as well.
Symons said it was about pushing a mindset for businesses to take account of the impact on the environment as well.
"A lot of these bars currently are pushing 'sustainability' by just cutting back their single use items, and that's it, they think that is sustainable," he said.
When the bar ran the initiative last year, Symons said it was embraced by locals with business turnover rising about 13 percent.
But on the environment front, the bar saved 30 coupe glasses going straight into landfill, and patrons' ecological awareness rose by 64 percent.
The bar asks customers who take in the initiative to fill in a questionnaire and ask if they are aware of how much waste goes into landfill and how much goes into the ocean.
"(It's) testing people's knowledge on their waste and then measuring their response to actual statistics," Symons said.
"That's where we can measure how close people get to the actual figures, it is a strange method but we are just trying to help create a field of data not previously explored.
"(We're) trying to see how much people actually take in from these initiatives and not just in for a cheap drink."
It's not the first time the Howln' Wolf has done their bit to help the environment.
To celebrate National Straw Day on January 3, the bar, which has already banned single-use straws, allowed punters to bring along their own metal straws.
"We generally have a strict no 'BYO straw' policy in place in the venue for obvious reasons but people really got around it," Symons said.
Punters ecological awareness rose 22 percent from this event.
Last February, the bar offered 20 percent off its take away wine and beer sales if customers bought their own renewable bag along, and was so-well received they plan to do it again before Easter.
Symons' said the hope that is that other bars in the region will join in on helping the environment.
"We have only done a couple of things so far but we are still a young bar and we hope some of the bigger guys in the area will jump on board with the sustainability push we are trying to get the ball rolling in Wollongong."