Stella McCartney on Vogue's January cover.

Vogue is getting serious.

The glossy magazine has in the past come under fire for not being representative enough — especially with cover stars.

But, as the new year approaches, editors in chief of Vogue’s 26 global editions have agreed to adhere to certain values for 2020, including striving to be representative of their readership.

“We speak with a unified voice across 26 editions standing for the values of diversity, responsibility and respect for individuals, communities and for our natural environment,” they said in a joint statement.

Among them are Anna Wintour, British Vogue’s Edward Enninful, Vogue Paris’ Emmanuelle Alt, Vogue Italy’s Emanuele Farneti and Vogue China’s Angelica Cheung.

They pledged to be socially responsible, represent people from all backgrounds, and to have a strong voice on current affairs and global issues.

In particular, the editors highlighted sustainability as one of the most important values, with 74 percent of Vogue readers rating sustainable fashion as important to them, while 78 percent expect Vogue to recommend sustainable fashion brands.

“I’m thrilled to join with the other Vogue editors around the world in celebrating Vogue values,” said Wintour, editor in chief of Vogue, U.S. artistic director and global content adviser at Condé Nast.

“And who better than Stella McCartney to be the first January cover star for U.S. Vogue? Her pioneering work around fashion and sustainability is a model of ingenuity and vision,” she added.

For his part, Roger Lynch, Condé’s new chief executive officer, believes that Vogue has the ability to move, influence and inspire — and with that, a responsibility to lead on the issues that matter most.

“For over a century, Condé Nast’s titles have driven the cultural conversation and propelled meaningful change around the world. This new commitment underscores what we can accomplish when we work together to leverage our global reach,” he said.

Last month, Condé pledged to the U.N.’s Fashion Industry Charter for Climate Action, becoming what the international body claims is the first media outlet to do so.

Working closely with the foundation as part of its New Plastics Economy Global Commitment, the media company, whose other titles include The New Yorker, GQ, Glamour, Wired and Vanity Fair, aims to carve a more sustainable roadmap to 2025, starting with its packaging.