diff --git a/FSCalendar/FSCalendar.h b/FSCalendar/FSCalendar.h
index 041b572..4900229 100644
--- a/FSCalendar/FSCalendar.h
+++ b/FSCalendar/FSCalendar.h
@@ -506,7 +506,7 @@ IB_DESIGNABLE
  @param position The month position for the cell
  @return An object representing a cell of the calendar, or nil if the cell is not visible or date is out of range.
  */
-- (__kindof FSCalendarCell *)cellForDate:(NSDate *)date atMonthPosition:(FSCalendarMonthPosition)position;
+- (nullable FSCalendarCell *)cellForDate:(NSDate *)date atMonthPosition:(FSCalendarMonthPosition)position;
 
 
 /**
diff --git a/FSCalendar/FSCalendar.m b/FSCalendar/FSCalendar.m
index 8e967b8..e629c2d 100644
--- a/FSCalendar/FSCalendar.m
+++ b/FSCalendar/FSCalendar.m
@@ -825,7 +825,7 @@ typedef NS_ENUM(NSUInteger, FSCalendarOrientation) {
     return cell;
 }
 
-- (FSCalendarCell *)cellForDate:(NSDate *)date atMonthPosition:(FSCalendarMonthPosition)position
+- (nullable FSCalendarCell *)cellForDate:(NSDate *)date atMonthPosition:(FSCalendarMonthPosition)position
 {
     NSIndexPath *indexPath = [self.calculator indexPathForDate:date atMonthPosition:position];
     return (FSCalendarCell *)[self.collectionView cellForItemAtIndexPath:indexPath];