Bill Gates has called for a tax on robots to make up for lost taxes from workers whose jobs are destroyed by automation.

The Microsoft founder and world’s richest man said the revenue from a robot tax could help fund more health workers and people in elderly and child care, areas that are still expected to rely on humans.

His comments come amid growing concerns about how robots and artificial intelligence will change the workforce, with experts predicting that most jobs will be rendered obsolete over the next 30 years.