diff --git a/apps/dav/lib/CalDAV/Activity/Backend.php b/apps/dav/lib/CalDAV/Activity/Backend.php
index 9f929dc195..73bd9b5daf 100644
--- a/apps/dav/lib/CalDAV/Activity/Backend.php
+++ b/apps/dav/lib/CalDAV/Activity/Backend.php
@@ -27,6 +27,7 @@ namespace OCA\DAV\CalDAV\Activity;
 
 use OCA\DAV\CalDAV\Activity\Provider\Calendar;
 use OCA\DAV\CalDAV\Activity\Provider\Event;
+use OCA\DAV\CalDAV\CalDavBackend;
 use OCP\Activity\IEvent;
 use OCP\Activity\IManager as IActivityManager;
 use OCP\IGroup;
@@ -415,6 +416,7 @@ class Backend {
 			$currentUser = $owner;
 		}
 
+		$classification = $objectData['classification'] ?? CalDavBackend::CLASSIFICATION_PUBLIC;
 		$object = $this->getObjectNameAndType($objectData);
 		$action = $action . '_' . $object['type'];
 
@@ -434,6 +436,11 @@ class Backend {
 		$users[] = $owner;
 
 		foreach ($users as $user) {
+			if ($classification === CalDavBackend::CLASSIFICATION_PRIVATE && $user !== $owner) {
+				// Private events are only shown to the owner
+				continue;
+			}
+
 			$event->setAffectedUser($user)
 				->setSubject(
 					$user === $currentUser ? $action . '_self' : $action,
@@ -446,7 +453,8 @@ class Backend {
 						],
 						'object' => [
 							'id' => $object['id'],
-							'name' => $object['name'],
+							'name' => $classification === CalDavBackend::CLASSIFICATION_CONFIDENTIAL && $user !== $owner ? 'Busy' : $object['name'],
+							'classified' => $classification === CalDavBackend::CLASSIFICATION_CONFIDENTIAL && $user !== $owner,
 						],
 					]
 				);
diff --git a/apps/dav/lib/CalDAV/Activity/Provider/Event.php b/apps/dav/lib/CalDAV/Activity/Provider/Event.php
index 378a18397e..666660cdb1 100644
--- a/apps/dav/lib/CalDAV/Activity/Provider/Event.php
+++ b/apps/dav/lib/CalDAV/Activity/Provider/Event.php
@@ -23,6 +23,7 @@
 
 namespace OCA\DAV\CalDAV\Activity\Provider;
 
+use OCA\DAV\CalDAV\CalDavBackend;
 use OCP\Activity\IEvent;
 use OCP\Activity\IEventMerger;
 use OCP\Activity\IManager;
@@ -131,14 +132,14 @@ class Event extends Base {
 					return [
 						'actor' => $this->generateUserParameter($parameters['actor']),
 						'calendar' => $this->generateCalendarParameter($parameters['calendar'], $this->l),
-						'event' => $this->generateObjectParameter($parameters['object']),
+						'event' => $this->generateClassifiedObjectParameter($parameters['object']),
 					];
 				case self::SUBJECT_OBJECT_ADD . '_event_self':
 				case self::SUBJECT_OBJECT_DELETE . '_event_self':
 				case self::SUBJECT_OBJECT_UPDATE . '_event_self':
 					return [
 						'calendar' => $this->generateCalendarParameter($parameters['calendar'], $this->l),
-						'event' => $this->generateObjectParameter($parameters['object']),
+						'event' => $this->generateClassifiedObjectParameter($parameters['object']),
 					];
 			}
 		}
@@ -168,4 +169,12 @@ class Event extends Base {
 
 		throw new \InvalidArgumentException();
 	}
+
+	private function generateClassifiedObjectParameter(array $eventData) {
+		$parameter = $this->generateObjectParameter($eventData);
+		if ($eventData['classified']) {
+			$parameter['name'] = $this->l->t('Busy');
+		}
+		return $parameter;
+	}
 }