10/09/2012 at 06:00 AM EDT
Frightful but delightful!
joined a group of girlfriends Sunday for a night out at the Los Angeles Haunted Hayride.
Before embarking on a private hayride, Perry and crew met up with Fashion Police
host George Kotsiopoulos and his friends.
Wearing ponchos to protect them from the splatter and gore, the group headed into a haunted maze.
"Katy was in there for about 30 minutes!" an onlooker tells PEOPLE. "She seemed to be having a ton of fun and shared lots of laughs with her friends."
"She loved being scared by all of the characters each time they snuck up on her!" the source adds.
– Melody Chiu