diff --git a/FSCalendar/FSCalendarTransitionCoordinator.m b/FSCalendar/FSCalendarTransitionCoordinator.m
index 14d4489..03d880a 100644
--- a/FSCalendar/FSCalendarTransitionCoordinator.m
+++ b/FSCalendar/FSCalendarTransitionCoordinator.m
@@ -553,7 +553,7 @@
     self.calendar.bottomBorder.fs_top = CGRectGetMaxY(targetBounds);
     self.calendar.contentView.fs_height = CGRectGetHeight(targetBounds)-self.calendar.scopeHandle.fs_height;
     self.calendar.daysContainer.fs_height = CGRectGetHeight(targetBounds)-self.calendar.preferredHeaderHeight-self.calendar.preferredWeekdayHeight-self.calendar.scopeHandle.fs_height;
-    [self.calendar.delegate calendar:self.calendar boundingRectWillChange:targetBounds animated:YES];
+    [[self.calendar valueForKey:@"delegateProxy"] calendar:self.calendar boundingRectWillChange:targetBounds animated:animated];
 }
 
 - (void)performForwardTransition:(FSCalendarTransition)transition fromProgress:(CGFloat)progress