McDonald's UK has admitted its "eco-friendly" paper straws cannot be recycled, but it's old plastic ones could be.
The fast food giant swapped out the straws in 2018.
However, customers complained it was difficult to drink milkshakes through the paper straws, so the restaurant chain strengthened them.
This means the straws must now be disposed of in general waste "until further notice," according to an internal memo obtained by The Sun.
"As a result of customer feedback we have strengthened our paper straws," a McDonald's UK spokesperson told BBC.
"So while the materials are recyclable their current thickness makes it difficult for them to be processed by our waste solution providers," they continued.
McDonald's UK uses 1.8 million straws every day, reports BBC.
The spokesperson says this is a temporary measure, and the company is working with its waste solution providers to find a fix.