diff --git a/lib/Controller/APIv2Controller.php b/lib/Controller/APIv2Controller.php
index 2270bef69..e0444a0c3 100644
--- a/lib/Controller/APIv2Controller.php
+++ b/lib/Controller/APIv2Controller.php
@@ -28,29 +28,14 @@
 use OCP\Notification\IManager as INotificationManager;
 
 class APIv2Controller extends OCSController {
-	/** @var string */
-	protected $filter;
-
-	/** @var int */
-	protected $since;
-
-	/** @var int */
-	protected $limit;
-
-	/** @var string */
-	protected $sort;
-
-	/** @var string */
-	protected $objectType;
-
-	/** @var int */
-	protected $objectId;
-
-	/** @var string */
-	protected $user;
-
-	/** @var bool */
-	protected $loadPreviews;
+	protected string $filter = 'all';
+	protected int $since = 0;
+	protected int $limit = 50;
+	protected string $sort = 'desc';
+	protected string $objectType = '';
+	protected int $objectId = 0;
+	protected string $user = '';
+	protected bool $loadPreviews = false;
 
 	public function __construct(
 		$appName,
@@ -71,26 +56,19 @@ public function __construct(
 	}
 
 	/**
-	 * @param string $filter
-	 * @param int $since
-	 * @param int $limit
-	 * @param bool $previews
-	 * @param string $objectType
-	 * @param int $objectId
-	 * @param string $sort
 	 * @throws InvalidFilterException when the filter is invalid
 	 * @throws \OutOfBoundsException when no user is given
 	 */
-	protected function validateParameters($filter, $since, $limit, $previews, $objectType, $objectId, $sort) {
-		$this->filter = \is_string($filter) ? $filter : 'all';
+	protected function validateParameters(string $filter, int $since, int $limit, bool $previews, string $objectType, int $objectId, string $sort): void {
+		$this->filter = $filter;
 		if ($this->filter !== $this->data->validateFilter($this->filter)) {
 			throw new InvalidFilterException('Invalid filter');
 		}
-		$this->since = (int)$since;
-		$this->limit = (int)$limit;
-		$this->loadPreviews = (bool)$previews;
-		$this->objectType = (string)$objectType;
-		$this->objectId = (int)$objectId;
+		$this->since = $since;
+		$this->limit = $limit;
+		$this->loadPreviews = $previews;
+		$this->objectType = $objectType;
+		$this->objectId = $objectId;
 		$this->sort = \in_array($sort, ['asc', 'desc'], true) ? $sort : 'desc';
 
 		if (($this->objectType !== '' && $this->objectId === 0) || ($this->objectType === '' && $this->objectId !== 0)) {
@@ -110,32 +88,15 @@ protected function validateParameters($filter, $since, $limit, $previews, $objec
 
 	/**
 	 * @NoAdminRequired
-	 *
-	 * @param int $since
-	 * @param int $limit
-	 * @param bool $previews
-	 * @param string $object_type
-	 * @param int $object_id
-	 * @param string $sort
-	 * @return DataResponse
 	 */
-	public function getDefault($since = 0, $limit = 50, $previews = false, $object_type = '', $object_id = 0, $sort = 'desc'): DataResponse {
+	public function getDefault(int $since = 0, int $limit = 50, bool $previews = false, string $object_type = '', int $object_id = 0, string $sort = 'desc'): DataResponse {
 		return $this->get('all', $since, $limit, $previews, $object_type, $object_id, $sort);
 	}
 
 	/**
 	 * @NoAdminRequired
-	 *
-	 * @param string $filter
-	 * @param int $since
-	 * @param int $limit
-	 * @param bool $previews
-	 * @param string $object_type
-	 * @param int $object_id
-	 * @param string $sort
-	 * @return DataResponse
 	 */
-	public function getFilter($filter, $since = 0, $limit = 50, $previews = false, $object_type = '', $object_id = 0, $sort = 'desc'): DataResponse {
+	public function getFilter(string $filter, int $since = 0, int $limit = 50, bool $previews = false, string $object_type = '', int $object_id = 0, string $sort = 'desc'): DataResponse {
 		return $this->get($filter, $since, $limit, $previews, $object_type, $object_id, $sort);
 	}
 
@@ -191,17 +152,7 @@ public function listFilters(): DataResponse {
 		return new DataResponse($filters);
 	}
 
-	/**
-	 * @param string $filter
-	 * @param int $since
-	 * @param int $limit
-	 * @param bool $previews
-	 * @param string $filterObjectType
-	 * @param int $filterObjectId
-	 * @param string $sort
-	 * @return DataResponse
-	 */
-	protected function get($filter, $since, $limit, $previews, $filterObjectType, $filterObjectId, $sort): DataResponse {
+	protected function get(string $filter, int $since, int $limit, bool $previews, string $filterObjectType, int $filterObjectId, string $sort): DataResponse {
 		try {
 			$this->validateParameters($filter, $since, $limit, $previews, $filterObjectType, $filterObjectId, $sort);
 		} catch (InvalidFilterException $e) {
diff --git a/lib/Data.php b/lib/Data.php
index 3262175df..06e7867af 100644
--- a/lib/Data.php
+++ b/lib/Data.php
@@ -226,7 +226,7 @@ public function storeMail(IEvent $event, int $latestSendTime): bool {
 	 * @return array
 	 *
 	 */
-	public function get(GroupHelper $groupHelper, UserSettings $userSettings, $user, $since, $limit, $sort, $filter, $objectType = '', $objectId = 0, bool $returnEvents = false) {
+	public function get(GroupHelper $groupHelper, UserSettings $userSettings, string $user, int $since, int $limit, string $sort, string $filter, string $objectType = '', int $objectId = 0, bool $returnEvents = false): array {
 		// get current user
 		if ($user === '') {
 			throw new \OutOfBoundsException('Invalid user', 1);
@@ -323,7 +323,7 @@ public function get(GroupHelper $groupHelper, UserSettings $userSettings, $user,
 	 *
 	 * @throws \OutOfBoundsException If $since is not owned by $user
 	 */
-	protected function setOffsetFromSince(IQueryBuilder $query, $user, $since, $sort) {
+	protected function setOffsetFromSince(IQueryBuilder $query, string $user, int $since, string $sort): array {
 		if (!$since) {
 			return $this->getFirstKnownActivityHeader($user, $sort);
 		}
@@ -331,7 +331,7 @@ protected function setOffsetFromSince(IQueryBuilder $query, $user, $since, $sort
 		$queryBuilder = $this->connection->getQueryBuilder();
 		$queryBuilder->select(['affecteduser', 'timestamp'])
 			->from('activity')
-			->where($queryBuilder->expr()->eq('activity_id', $queryBuilder->createNamedParameter((int)$since)));
+			->where($queryBuilder->expr()->eq('activity_id', $queryBuilder->createNamedParameter($since)));
 		$result = $queryBuilder->executeQuery();
 		$activity = $result->fetch();
 		$result->closeCursor();
diff --git a/tests/Controller/APIv2ControllerTest.php b/tests/Controller/APIv2ControllerTest.php
index ebdb1a147..b133a48db 100644
--- a/tests/Controller/APIv2ControllerTest.php
+++ b/tests/Controller/APIv2ControllerTest.php
@@ -140,9 +140,11 @@ public function testValidateParametersFilter(string $param, string $filter): voi
 			->method('validateFilter')
 			->with($param)
 			->willReturn($filter);
+		$userMock = $this->createMock(IUser::class);
+		$userMock->method('getUID')->willReturn('testuser');
 		$this->userSession->expects($this->once())
 			->method('getUser')
-			->willReturn($this->createMock(IUser::class));
+			->willReturn($userMock);
 
 		self::invokePrivate($this->controller, 'validateParameters', [$param, 0, 0, false, '', 0, 'desc']);
 		$this->assertSame($filter, self::invokePrivate($this->controller, 'filter'));
@@ -173,19 +175,21 @@ public static function dataValidateParametersObject(): array {
 		return [
 			['type', 42, 'type', 42],
 			['type', '42', 'type', 42],
-			[null, '42', '', 0],
-			['type', null, '', 0],
+			['', 42, '', 0],
+			['type', 0, '', 0],
 		];
 	}
 
 	#[DataProvider('dataValidateParametersObject')]
-	public function testValidateParametersObject(?string $type, mixed $id, string $expectedType, int $expectedId): void {
+	public function testValidateParametersObject(string $type, mixed $id, string $expectedType, int $expectedId): void {
 		$this->data->expects($this->once())
 			->method('validateFilter')
 			->willReturnArgument(0);
+		$userMock = $this->createMock(IUser::class);
+		$userMock->method('getUID')->willReturn('testuser');
 		$this->userSession->expects($this->once())
 			->method('getUser')
-			->willReturn($this->createMock(IUser::class));
+			->willReturn($userMock);
 
 		self::invokePrivate($this->controller, 'validateParameters', ['all', 0, 0, false, $type, $id, 'desc']);
 		$this->assertSame($expectedType, self::invokePrivate($this->controller, 'objectType'));
@@ -229,9 +233,11 @@ public function testValidateParameters(string $param, mixed $value, string $memb
 		$this->data->expects($this->once())
 			->method('validateFilter')
 			->willReturnArgument(0);
+		$userMock = $this->createMock(IUser::class);
+		$userMock->method('getUID')->willReturn('testuser');
 		$this->userSession->expects($this->once())
 			->method('getUser')
-			->willReturn($this->createMock(IUser::class));
+			->willReturn($userMock);
 
 		self::invokePrivate($this->controller, 'validateParameters', $params);
 		$this->assertSame($expectedValue, self::invokePrivate($this->controller, $memberName));