diff --git a/aleksis/core/mixins.py b/aleksis/core/mixins.py
index c331b0cf1df9aeacad3a7b5f3305a67a7e1c30f4..22c16d3469a1e07070c309115078fa55b5bf6dd7 100644
--- a/aleksis/core/mixins.py
+++ b/aleksis/core/mixins.py
@@ -726,9 +726,10 @@ class CalendarEventMixin(DAVResource, RegistryObject, is_registry=True):
     The list of objects used to create the calendar feed have to be provided by
     the method `get_objects` class method. It's mandatory to implement this method.
 
-    The list of objects whose respective events should be marked as blocking the respective
-    entities passed to it (persons, groups, ...) have to be provided by the `get_busy_objects`
-    class method. If the method is not implemented, no objects will be marked.
+    The list of objects whose respective events should be marked as being relevant to the
+    availability of the respective entities passed to it (persons, groups, ...) have to be
+    provided by the `get_availability_objects` class method. If the method is not implemented,
+    no objects will be marked.
 
     To provide the data for the events, a certain set of class methods can be implemented.
     The following iCal attributes are supported:
@@ -886,7 +887,7 @@ class CalendarEventMixin(DAVResource, RegistryObject, is_registry=True):
         return qs
 
     @classmethod
-    def get_busy_objects(cls, request: HttpRequest, obj) -> Iterable:
+    def get_availability_objects(cls, request: HttpRequest, obj) -> Iterable:
         """Return the objects whose events should be marked as blocking."""
         return None
 
diff --git a/aleksis/core/models.py b/aleksis/core/models.py
index 9205d186b8471ee61f30ea037f42b94f083790e4..82284ff5294bb15cbc8ea0b7ee5e7cd16d890070 100644
--- a/aleksis/core/models.py
+++ b/aleksis/core/models.py
@@ -1739,13 +1739,13 @@ class CalendarEvent(
             calendar_alarm.get_alarm(request) for calendar_alarm in reference_object.alarms.all()
         ]
 
-    def get_availability_persons(self) -> QuerySet:
+    def get_availability_persons(self) -> list[Person]:
         """Return the persons whose availability is affected by the event."""
-        raise NotImplementedError()
+        return []
 
-    def get_availability_groups(self) -> QuerySet:
+    def get_availability_groups(self) -> list[Group]:
         """Return the groups whose availability is affected by the event."""
-        raise NotImplementedError()
+        return []
 
     @classmethod
     def get_objects(