Lululemon has a sheerness problem.

The yoga-apparel retailer's shares tumbled late Monday after saying it has pulled some of its popular pants from stores, after a mistake by a supplier left the pants too see-through.

Lululemon Athletica Inc. said the glitch involved pants using its signature fabric, known as Luon, that arrived in stores March 1. The retailer is offering refunds to customers.

The glitch could be a big hit to the company, affecting 17% of the bottoms it had in stock. Lululemon said the incident would reduce its expected first-quarter sales to $333 million to $343 million, down from the $350 million to $355 million it had previously expected.

The company's shares fell more than 6% in after-hours trading to $61.75 following the news. They had already slipped nearly 4% during the day.