For Portaru, the decision is “highly problematic.”

“It ultimately allows private businesses to implement rules which violate the fundamental right to freedom of religion,” she said. “It is the court’s duty to accommodate different convictions and beliefs rather than force a so-called neutrality.”

At the same time, the European Court of Justice said that national courts should determine that there is no particular disadvantage for people of a particular religion or belief unless it is “objectively justified by a legitimate aim” and workplace practices follow “appropriate and necessary” practices. It said the Belgian court would have needed to determine whether Achbita could have been offered another position not in sight of customers.

The court rejected specific treatment of religious individuals based on a customer’s complaint, as in a French case where a firm allegedly fired a design engineer after a customer complained about her Islamic headscarf.

Some forms of religious expression in Europe face legal penalties.

A ban on teachers wearing the headscarf was ruled unconstitutional in a German court in 2015. In Austria and the German state of Bavaria, full-face veils are banned in public.

In 2013, four Christian British Airways employees won a legal case in the European Court of Human Rights, which ruled their employer engaged in illegal discrimination for telling them they could not wear their crosses.