Ios8 distanceFromLocation在iOS 8和iOS 9之间返回不同的结果

我使用CLLocation的

distanceFromLocation

方法计算两个位置之间的距离，如下所示。它在iOS 8和iOS 9之间返回不同的结果
有人知道为什么吗？谢谢

CLLocation *locationA = [[CLLocation alloc] initWithLatitude:39.861667 longitude:-104.673167];
CLLocation *locationB = [[CLLocation alloc] initWithLatitude:33.942500 longitude:-118.408075];

// Calculate distance between 2 locations
CLLocationDistance routeDistance = [locationA distanceFromLocation:locationB];

NSLog(@"Distance A - B : %f", routeDistance);

==>结果：
距离A-B:
iOS 8:1383761.019303

---

iOS 9:1387015.203345

也许苹果决定改变

distance fromLocation