diff --git a/lib/models/calendar/CalendarDate.class.php b/lib/models/calendar/CalendarDate.class.php
index 23ea8af3daa4137b8e1900a03c0bf43cdf989209..d5b96270f358887a96d3678a0dcaecd1608c4462 100644
--- a/lib/models/calendar/CalendarDate.class.php
+++ b/lib/models/calendar/CalendarDate.class.php
@@ -254,7 +254,7 @@ class CalendarDate extends SimpleORMap implements PrivacyObject
             ['calendar_date_id' => $this->id]
         );
         foreach ($course_assignments as $course_assignment) {
-            if ($course_assignment->course->calendarWritable($range_id)) {
+            if ($course_assignment->course->isCalendarWritable($range_id)) {
                 return true;
             }
         }