I think you want to replace `+=` by `=` here: https://github.com/SwiftKickMobile/TLIndexPathTools/blob/ca47649036081ec5b1220926ae072dab908301ea/TLIndexPathTools/Data%20Model/TLIndexPathItem.m#L53-57 Right now, you're effectively calculating: hash = 32 * hash + [self.identifier hash];