Brussels, Belgium - Billie Eilish is holding true to her word as an environmental activist as she stuns fans by flying on an economy flight despite her A-list status.

The 21-year-old was spotted by fans flying on a commercial airline from Belgium, likely en route to her next round of concerts.

A fan-captured TikTok posted on Saturday gave a glimpse of Eilish on board, with the singer later confirming it was indeed her with a selfie taken from the plane.

The Ocean Eyes artist has been a devoted advocate of environmental and climate-related causes, and while many stars of her caliber have been criticized for excessive use of private jets, she continues to set herself apart with her latest move.

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Earlier this month, Eilish continued her efforts with a partially solar-powered headlining set at Lollapalooza in Chicago.

Prior to that, the Grammy winner hosted a number of environmental activism activities on her Happier Than Ever tour with reusable water bottle stations, promotion of environmental nonprofits, and voter registration.

In June, Eilish headlined a performance in Paris, France, hosted by NGO Global Citizen, aimed at raising awareness of the climate crisis.