View controller dealloc not called when using NSNotificationCenter code block method with ARC

When I use -addObserverForName: object: queue: usingBlock: for NSNotificationCenter in the -viewDidLoad: method of my view controller, the -dealloc method ends up not being called.

(When I remove -addObserverForName: object: queue: usingBlock:, -dealloc is called again.)

Using -addObserver: selector: name: object: doesn't seem to have this problem. What am I doing wrong? (My project is using ARC.)

Below is an example of my implementation, in case I'm doing something wrong here:

[[NSNotificationCenter defaultCenter] addObserverForName:@"Update result"
                                                  object:nil
                                                   queue:nil
                                              usingBlock:^(NSNotification *note) {
                                                  updateResult = YES;
                                              }];

Thanks in advance for any help.

I've tried adding the following (to no avail):

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

    if ([self isMovingFromParentViewController]) {
        [[NSNotificationCenter defaultCenter] removeObserver:self];
    }
}