ARC and UIAlertView: unrecognized selector sent to instance

Here is how I show UIAlertView and the delegate clickedButtonAtIndex -

UIAlertView *alert =
    [[UIAlertView alloc] initWithTitle: @"title"
                               message: @"message"
                              delegate: self
                     cancelButtonTitle: @"Cancel"
                     otherButtonTitles: @"Continue", nil];

    [alert show];


- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    //something
}

This piece of code works perfectly without ARC. But with ARC it throws this error - Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFType alertView:clickedButtonAtIndex:]: unrecognized selector sent to instance 0x859d790'

Any ideas on why the delegate is throwing this error?