US President Donald Trump signed an executive order mandating that truck drivers in the US are proficient in English—a requirement that has raised concerns among Sikh groups that say it can have a “discriminatory impact” and create barriers to employment.

“Proficiency in English is a non-negotiable safety requirement for professional drivers. They should be able to read and understand traffic signs, communicate with traffic safety, border patrol, agricultural checkpoints, and cargo weight-limit station officers,” the order says.