Mars bars have been given a new look with recyclable paper wrappers instead of plastic.
It is part of a pilot, trialling more environmentally friendly materials for Mars Food's chocolate bars.
The new packaging will be rolled out at 500 Tesco stores in the UK from Monday.
The move follows chocolate rivals, Nestle, which has been using paper packaging for Smarties since January 2021 and on some Quality Street sweets since December 2022.
Nine of the 11 Quality Street traditional sweets moved to paper-based packaging.
The Orange Crunch and the Green Triangle remained in their foil wrappers as these are recyclable already.
Mars say it's a challenge to find the right paper packaging solution with an "adequate level of barrier properties to protect the chocolate".
Mars's current plastic wrappings are not recyclable, as is the case for many items including crisp packets and many chocolate bar wrappers. This leads to them accumulating in landfill and polluting waters.
In the Philippines, which sees tonnes of single-use plastics wash up on its shores, such packaging is repurposed to make bricks for building by being stuffed in to bottles and stacked.
The RSPCA says that the problem with single-use plastic waste is that it does not break down, and that it only breaks up into smaller and smaller parts, which impacts environment and wildlife for many years in the future.
The government in January announced a ban on single-use plastics such as plastic cutlery, plates and polystyrene trays, although the ban has not yet come in to effect.
Plastic straws were banned in the UK in 2020, with India following suit in 2022.
Meanwhile, France banned the use of single-use plastics in takeaway food venues in January.
Mars Incorporated said the change will make "200 million bars per year carbon neutral in the UK, Ireland and Canada".
Andrew Flood, Tesco packaging development manager, said he was "delighted to partner with Mars", adding that the initiative aligned with Tesco's "own strategy of removing plastic and packaging" in its business.