The children’s author J.K. Rowling, writer of the Harry Potter series, has announced that she will publish a book of wizarding fairy tales in December and donate the proceeds to her charity for disadvantaged children, reports Reuters.

The book will sell for $12.99, according to Bloomsbury Publishing and Scholastic, and Amazon.com will produce up to 100,000 collector’s edition copies that will sell for $100 each.

Proceeds from the sales of the books are anticipated to reach $8-million.