I am stuck with this problem. I have the following .h file:

```
#import <UIKit/UIKit.h>

@protocol MapSettingsViewDelegate

- (void)settingsDidUpdate:(BOOL)scheme;

@end

@interface MapSettingsViewController : UIViewController

@property (nonatomic, assign) id <MapSettingsViewDelegate> delegate;
@property (nonatomic, strong) IBOutlet UINavigationBar *navBar;
@property (nonatomic, strong) IBOutlet UINavigationItem *titleItem;
@property (nonatomic, strong) IBOutlet UITableView *TableView;

- (id)init;
- (IBAction)saveAction:(id)sender;

@end

```

When I declare the following:

```
@interface MapViewController : UIViewController <MapSettingsViewDelegate>

```

The compiler complains with the following message:

```
Cannot find protocol declaration for 'MapSettingsViewDelegate'

```

I have the same kind of delegate declaration in other files in the same project that are compiled without a glitch. I spent the last four hours trying to figuring out what I am doing wrong. Cleaning the project does not nothing.