Greta Thunberg turned 18 on Sunday, and she thanked her fans with a snarky Twitter message about how she was celebrating.

The Swedish activist has been known for her sarcasm and wit since coming onto the world stage at age 15, so it might be no surprise she would have some fun with her birthday message using the same tone.

On top of Thunberg’s climate activism, she has used her platform to be philanthropic. She won the first Gulbenkian Prize for Humanity and donated a portion of the $1.14 million prize to fighting coronavirus in the Brazilian Amazon. She also donated $100,000 from another prize received from Human Act, to the United Nations Children’s Fund, to help children impacted by Covid-19.