A national children's helpline says it's ready to deal with calls from Potter fans who feel unhappy after the last book in the series goes on sale.
Childline took loads of calls from kids who were upset when Take That split in 1996 and say a similar thing may happen with the end of the Potter books.
It said the death of any big characters in Harry Potter and the Deathly Hallows could be very hard on younger readers.
The book will be available from the first minute of Saturday morning.
"Death and loss can make children upset, angry and afraid," said a Childline spokesman.
"For many children, Harry Potter and his friends have become a major part of their childhood.
"The story could bring back unhappy memories for children who have lost friends, relatives or pets."