France’s highest court for administrative justice, the Conseil d’Etat, issued two orders Sunday declaring that face masks can be made mandatory in large areas with a high risk of COVID-19 contamination.

In a press statement, the court said that “the wearing of the mask can be imposed so that this obligation is consistent and easy to apply to the citizens.” The court further specified that “these extended perimeters must be delimited—and justified— by the existence of several areas with a high risk of contamination.”

The orders come after two prefects (regional representatives at the state level) imposed mask-mandates on “public roads and in all places open to the public” in the departments of Bas-Rhin and Rhône in late August. The orders were appealed in administrative courts in the cities of Strasbourg and Lyon, where, in both cases, “the judges had ordered the prefects to modify their decrees to limit the obligation to wear the mask to places and times characterized by a high population density.”

Moving forward, the court stressed, “the simplicity and readability of an obligation, such as that of wearing a mask, are necessary for its good knowledge and its correct application.” Finally, the judge noted that the decrees “must take into account the constraint that [they] represent for the inhabitants, who must also respect this obligation in public transport and, the more often, in their school or university or at their workplace.”

The summary judge of the Council of State confirms, first of all, that the circulation of the COVID-19 virus is accelerating in the two departments and that in the current state of knowledge, systematically wear[ing] a mask outdoors is justified in the presence of a high density of people or when respect for physical distance cannot be guaranteed.