If you picked up a pair of eclipse-viewing glasses while grabbing your morning cup of joe from a Dutch Bros. Coffee this weekend, you don’t want to actually wear them during today’s eclipse event: The coffee chain is recalling the glasses over concerns they might not be safe. 

Just hours before the solar eclipse is set to take place, Dutch Brothers Coffee warned customers not to use the special viewing glasses — which were handed out at several locations recently — noting that they might not meet safety requirements.

Related: Here’s A Giant List Of Solar Eclipse Promotions

Eclipse-viewing glasses are essential because they let us safely look at the sun while it’s in partial eclipse, before the moon moves in front of it fully.

Dutch Bros., which operates more than 280 stores in seven states, notes that it purchased the glasses after receiving certification of ISO compliance from the manufacturer. However, further investigation led the company to question this certification.

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The chain did not specify what its investigation uncovered or how many of the glasses were given away at stores.

“Your safety is of the utmost importance to us, so we are issuing this voluntary recall,” the company said. “If you received a pair of these glasses, DO NOT USE THEM TO VIEW THE ECLIPSE.”

Instead, customers who received a pair of the glasses are being asked to return them to same location.

In attempt to make up for the recall, and customers potentially missing the eclipse, Dutch Bros. says affected guests will receive a free drink of any size when they return the glasses.

For a safe eclipse viewing experience, NASA has made the following eclipse glasses tips:

• The glasses should have certification information, and bear the designated ISO 12312-2 international standard.
• The actual manufacturer’s name and address should be printed somewhere on the glasses.
• Don’t use glasses that are wrinkled, scratched, or more than three years old.
• Don’t use regular sunglasses, no matter how dark they are.

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