Some kids are not content to wait around while the grown-ups sort out the future of our planet. Two of them, 9-year-old Ella and 7-year-old Caitlin, have launched a petition on Change.org requesting that McDonald’s and Burger King stop giving out plastic toys with their kid’s meals, Thrillist reports.

“Children only play with the plastic toys they give us for a few minutes before they get thrown away and harm animals and pollute the sea,” the British girls wrote on Change.org. “We want anything they give us to be sustainable so we can protect the planet for us and for future generations.” The petition has almost 400,000 signatures so far, and their current goal is to reach 500,000.

McDonald's

Last October, UK environment minister Thérèse Coffey also implored McDonald’s to stop giving out plastic toys, suggesting instead that they develop smartphone-friendly games to accompany the meals. At the time, a UK McDonald’s spokesman acknowledged the importance of reducing plastic waste and cited their promise to switch to paper straws, but countered the assumption that the plastic toys were only used for a few minutes, telling The Telegraph that they “provide many more fun-filled hours at home, too.”

The fast food giant did study the environmental effects of their toys last year and found that they are hard to recycle, since they’re manufactured from various types of plastic. As a result, McDonald’s is researching more Earth-friendly ways to make their toys. A Burger King representative told The Wall Street Journal that it, too, is exploring “alternative toy solutions.”

But according to Ella and Caitlin, “It’s not enough to make recyclable plastic toys—big, rich companies shouldn’t be making toys out of plastic at all.” The young activists themselves recycle as much as they can, and even hung a poster in their window about saving the planet.

You can sign their petition here, and learn how to reduce your own environmental impact.

[h/t Thrillist]