Property not found even with import

Question

I have a property called currentViewController which I declare in my DetailViewController as:

@property (nonatomic, assign) UIViewController *currentViewController;

and import it in my MasterViewController. For some reason the class is not seeing this property unless I explicitly cast it:

((DetailViewController *)detailViewController).currentViewController

If I don't cast it I get the error message 'Request for member "currentViewController" in something not a structure or union.' detailViewController is declared as type of DetailViewController. What gives?