diff --git a/event/templates/event/calendar.html b/event/templates/event/calendar.html
index a894ce9..73750a9 100644
--- a/event/templates/event/calendar.html
+++ b/event/templates/event/calendar.html
@@ -47,7 +47,7 @@
                 <span class="cal-event-description">{{ activity.description }}</span>
                 <span class="cal-event-url">{% url "event:activity" activity.id %}</span>
 
-                {% if activity.has_perm %}
+                {% if activity|get_herited:'has_perm' %}
                 <span class="cal-event-has-perms">1</span>
                 <span class="cal-event-min-nb-perms">{{ activity|get_herited:'min_perm' }}</span>
                 <span class="cal-event-max-nb-perms">{{ activity|get_herited:'max_perm' }}</span>