Lego has unveiled its first toy brick made entirely from recycled plastic - but eco-conscious builders will have to wait a while before it appears in their sets.
The Danish company revealed the brick, made from PET plastic from discarded bottles, is the first made from recycled materials that meets quality and safety standards.
More importantly for Lego fans, however, is that it also meets clutch power requirements - that's how well it sticks with other bricks.
The prototype has come after more than 150 people worked on sustainable solutions for the company and more than 250 different variations of PET plastic material were tested.
And it's all part of the toy giant's ambition to make its products - made from 90,000 tonnes of plastic - from sustainable sources by 2030.
"We are super excited about this breakthrough," said Tim Brooks, Lego's vice president of environmental responsibility.
"The biggest challenge on our sustainability journey is rethinking and innovating new materials that are as durable, strong and high quality as our existing bricks - and fit with Lego elements made over the past 60 years."
But that doesn't mean Kiwi fans of the iconic toy will be using them any time soon.
More testing and development needs to happen before the company moves to the pilot production stage, and that's expected to take at least a year.
"We know kids care about the environment and want us to make our products more sustainable," Brooks said.
"Even though it will be a while before they will be able to play with bricks made from recycled plastic, we want to let kids know we're working on it and bring them along on the journey with us.
"Experimentation and failing is an important part of learning and innovation. Just as kids build, unbuild and rebuild with Lego bricks at home, we're doing the same in our lab," he said.
The company has said it will invest up to US$400 million up to the end of next year to move its sustainability ambitions forward
"We still have a long way to go on our journey but are pleased with the progress we're making," Brooks said.