Buy a pack of cigarettes today and chances are you’ll see a prominent warning that the product may be harmful to human health. But many cigarettes should include a second warning too: “This product may be made with child labor.”

A young girl ties tobacco leaves onto sticks to prepare them for curing in East Lombok, West Nusa Tenggara.

Most smokers probably don’t realize that the tobacco in their cigarettes may be tainted by child labor. But as recent Human Rights Watch research shows, this is a particular problem in Indonesia, where kids as young as 8 work in hazardous conditions on small-scale tobacco farms to help support their families. They are exposed to nicotine and toxic pesticides, and many suffer nausea, vomiting, and other symptoms consistent with acute nicotine poisoning, which can happen when people absorb nicotine through their skin. The tobacco farmed by children is bought up by multinationals like Philip Morris International and British American Tobacco, as well as big Indonesian firms, who buy either directly from the farmers or through intermediary traders or suppliers. The tobacco then ends up in cigarettes smoked in Indonesia and all over the world.

While most multinationals bar their suppliers from using children to perform the most dangerous tasks on tobacco farms, none of them ban youngsters from all work involving direct contact with tobacco – the only policy that we believe would properly protect children from nicotine exposure. Moreover, when multinationals buy their tobacco from traders on the open market in Indonesia, they do no due diligence to trace the leaf back to the farms where it was grown, so they have no way of knowing whether child labor was involved. This goes against the the United Nation’s Guiding Principles on Business and Human Rights, which state that companies should adopt effective measures to identify any abuses present in their supply chains and address them.

But children don’t need to keep getting sick, and change is possible. Investors can push companies in the right direction.

This week, the nonprofit group Facing Finance published its fifth annual Dirty Profits report, which informs investors about human rights abuses in the supply chains of major multinational firms. Investors can use tools like these to raise their concerns with other investors or the company itself, or introduce shareholder resolutions demanding that companies stamp out abuse in their supply chains.

In the next few months, just as tobacco growing gets underway again in Indonesia, multinational tobacco companies will hold their annual shareholder meetings. It’s the perfect time for investors to speak out, and urge companies to do more to end child labor.