Starbucks is celebrating International Friendship Day with a buy one, get one free deal on macchiatos this weekend.

As part of Starbucks' "Meet for Macchiatos" promotion, customers can buy a macchiato at any participating store and get a free one to share.

The deal started Thursday and is valid through Monday between 2 p.m. and 5 p.m.

Sunday is International Friendship Day, but Starbucks is making it an extended weekend celebration.