@@ -20,16 +20,20 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
 #import <ObjFW/OFObject.h>
+
+OF_ASSUME_NONNULL_BEGIN
 
 @interface IRCUser: OFObject <OFCopying>
 {
 	OFString *_nickname, *_username, *_hostname;
 }
 
 @property (readonly, nonatomic) OFString *nickname, *username, *hostname;
 
 + (instancetype)IRCUserWithString: (OFString *)string;
-- initWithString: (OFString *)string;
+- (instancetype)initWithString: (OFString *)string OF_DESIGNATED_INITIALIZER;
 @end
+
+OF_ASSUME_NONNULL_END