diff --git a/lib/Capabilities.php b/lib/Capabilities.php
index 4a128f891..984e86240 100644
--- a/lib/Capabilities.php
+++ b/lib/Capabilities.php
@@ -23,9 +23,9 @@ class Capabilities implements ICapability {
 	 *
 	 * @return array{
 	 *     notifications: array{
-	 *         ocs-endpoints: string[],
-	 *         push: string[],
-	 *         admin-notifications: string[],
+	 *         ocs-endpoints: list<string>,
+	 *         push: list<string>,
+	 *         admin-notifications: list<string>,
 	 *     },
 	 * }
 	 */
diff --git a/lib/Controller/APIController.php b/lib/Controller/APIController.php
index f132df148..07f41182a 100644
--- a/lib/Controller/APIController.php
+++ b/lib/Controller/APIController.php
@@ -49,7 +49,7 @@ public function __construct(
 	 * @param string $userId ID of the user
 	 * @param string $shortMessage Subject of the notification
 	 * @param string $longMessage Message of the notification
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND|Http::STATUS_INTERNAL_SERVER_ERROR, null, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND|Http::STATUS_INTERNAL_SERVER_ERROR, null, array{}>
 	 * @deprecated 30.0.0
 	 *
 	 * 200: Notification generated successfully
diff --git a/lib/Controller/EndpointController.php b/lib/Controller/EndpointController.php
index c23ed6f18..2da411929 100644
--- a/lib/Controller/EndpointController.php
+++ b/lib/Controller/EndpointController.php
@@ -56,7 +56,7 @@ public function __construct(
 	 * Get all notifications
 	 *
 	 * @param string $apiVersion Version of the API to use
-	 * @return DataResponse<Http::STATUS_OK, NotificationsNotification[], array{'X-Nextcloud-User-Status': string}>|DataResponse<Http::STATUS_NO_CONTENT, null, array{X-Nextcloud-User-Status: string}>
+	 * @return DataResponse<Http::STATUS_OK, list<NotificationsNotification>, array{'X-Nextcloud-User-Status': string}>|DataResponse<Http::STATUS_NO_CONTENT, null, array{X-Nextcloud-User-Status: string}>
 	 *
 	 * 200: Notifications returned
 	 * 204: No app uses notifications
@@ -175,8 +175,8 @@ public function getNotification(string $apiVersion, int $id): DataResponse {
 	 * Check if notification IDs exist
 	 *
 	 * @param string $apiVersion Version of the API to use
-	 * @param int[] $ids IDs of the notifications to check
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST, int[], array{}>
+	 * @param list<int> $ids IDs of the notifications to check
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST, list<int>, array{}>
 	 *
 	 * 200: Existing notification IDs returned
 	 * 400: Too many notification IDs requested
@@ -195,10 +195,10 @@ public function confirmIdsForUser(string $apiVersion, array $ids): DataResponse
 			return new DataResponse([], Http::STATUS_BAD_REQUEST);
 		}
 
-		$ids = array_unique(array_filter(array_map(
+		$ids = array_values(array_unique(array_filter(array_map(
 			static fn ($id) => is_numeric($id) ? (int)$id : 0,
 			$ids
-		)));
+		))));
 
 		$existingIds = $this->handler->confirmIdsForUser($this->getCurrentUser(), $ids);
 		return new DataResponse($existingIds, Http::STATUS_OK);
@@ -208,7 +208,7 @@ public function confirmIdsForUser(string $apiVersion, array $ids): DataResponse
 	 * Delete a notification
 	 *
 	 * @param int $id ID of the notification
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, null, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<empty>, array{}>|DataResponse<Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, null, array{}>
 	 *
 	 * 200: Notification deleted successfully
 	 * 403: Deleting notification for impersonated user is not allowed
@@ -240,7 +240,7 @@ public function deleteNotification(int $id): DataResponse {
 	/**
 	 * Delete all notifications
 	 *
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_FORBIDDEN, null, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<empty>, array{}>|DataResponse<Http::STATUS_FORBIDDEN, null, array{}>
 	 *
 	 * 200: All notifications deleted successfully
 	 * 403: Deleting notification for impersonated user is not allowed
diff --git a/lib/Controller/PushController.php b/lib/Controller/PushController.php
index 26957bc22..4fac070ce 100644
--- a/lib/Controller/PushController.php
+++ b/lib/Controller/PushController.php
@@ -50,7 +50,7 @@ public function __construct(
 	 * @param string $pushTokenHash Hash of the push token
 	 * @param string $devicePublicKey Public key of the device
 	 * @param string $proxyServer Proxy server to be used
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_CREATED, NotificationsPushDevice, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{message: string}, array{}>|DataResponse<Http::STATUS_UNAUTHORIZED, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_CREATED, NotificationsPushDevice, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{message: string}, array{}>|DataResponse<Http::STATUS_UNAUTHORIZED, list<empty>, array{}>
 	 *
 	 * 200: Device was already registered
 	 * 201: Device registered successfully
@@ -131,7 +131,7 @@ public function registerDevice(string $pushTokenHash, string $devicePublicKey, s
 	/**
 	 * Remove a device from push notifications
 	 *
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_ACCEPTED|Http::STATUS_UNAUTHORIZED, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{message: string}, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_ACCEPTED|Http::STATUS_UNAUTHORIZED, list<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{message: string}, array{}>
 	 *
 	 * 200: No device registered
 	 * 202: Device removed successfully
diff --git a/lib/Controller/SettingsController.php b/lib/Controller/SettingsController.php
index 0327cfc08..7b7a295ae 100644
--- a/lib/Controller/SettingsController.php
+++ b/lib/Controller/SettingsController.php
@@ -36,7 +36,7 @@ public function __construct(
 	 * @param int $batchSetting How often E-mails about missed notifications should be sent (hourly: 1; every three hours: 2; daily: 3; weekly: 4)
 	 * @param string $soundNotification Enable sound for notifications ('yes' or 'no')
 	 * @param string $soundTalk Enable sound for Talk notifications ('yes' or 'no')
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<empty>, array{}>
 	 *
 	 * 200: Personal settings updated
 	 */
@@ -57,7 +57,7 @@ public function personal(int $batchSetting, string $soundNotification, string $s
 	 * @param int $batchSetting How often E-mails about missed notifications should be sent (hourly: 1; every three hours: 2; daily: 3; weekly: 4)
 	 * @param string $soundNotification Enable sound for notifications ('yes' or 'no')
 	 * @param string $soundTalk Enable sound for Talk notifications ('yes' or 'no')
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<empty>, array{}>
 	 *
 	 * 200: Admin settings updated
 	 */
diff --git a/lib/Handler.php b/lib/Handler.php
index a78e3aac1..b69246d76 100644
--- a/lib/Handler.php
+++ b/lib/Handler.php
@@ -183,8 +183,8 @@ public function getById(int $id, string $user): INotification {
 	/**
 	 * Confirm that the notification ids still exist for the user
 	 *
-	 * @param int[] $ids
-	 * @return int[]
+	 * @param list<int> $ids
+	 * @return list<int>
 	 */
 	public function confirmIdsForUser(string $user, array $ids): array {
 		$query = $this->connection->getQueryBuilder();
diff --git a/lib/ResponseDefinitions.php b/lib/ResponseDefinitions.php
index e5cf665c1..fabe09e48 100644
--- a/lib/ResponseDefinitions.php
+++ b/lib/ResponseDefinitions.php
@@ -57,7 +57,7 @@
  *     subject: string,
  *     message: string,
  *     link: string,
- *     actions: NotificationsNotificationAction[],
+ *     actions: list<NotificationsNotificationAction>,
  *     subjectRich?: string,
  *     subjectRichParameters?: array<string, NotificationsRichObjectParameter>,
  *     messageRich?: string,