diff --git a/lib/Cron/DeleteCron.php b/lib/Cron/DeleteCron.php
index cdf35cedb..0d769deef 100644
--- a/lib/Cron/DeleteCron.php
+++ b/lib/Cron/DeleteCron.php
@@ -35,10 +35,17 @@ use OCA\Deck\Db\BoardMapper;
 
 class DeleteCron extends Job {
 
+	/** @var BoardMapper */
+	private $boardMapper;
+
 	public function __construct(BoardMapper $boardMapper) {
 		$this->boardMapper = $boardMapper;
 	}
 
+	/**
+	 * @param $argument
+	 * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+	 */
 	protected function run($argument) {
 		$boards = $this->boardMapper->findToDelete();
 		foreach ($boards as $board) {
diff --git a/lib/Cron/ScheduledNotifications.php b/lib/Cron/ScheduledNotifications.php
index faa7660e4..d553492dc 100644
--- a/lib/Cron/ScheduledNotifications.php
+++ b/lib/Cron/ScheduledNotifications.php
@@ -43,6 +43,10 @@ class ScheduledNotifications extends Job {
 		$this->notificationHelper = $notificationHelper;
 	}
 
+	/**
+	 * @param $argument
+	 * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+	 */
 	public function run($argument) {
 		// Notify board owner and card creator about overdue cards
 		$cards = $this->cardMapper->findOverdue();
diff --git a/lib/Db/CardMapper.php b/lib/Db/CardMapper.php
index 8e9fdcc34..b13eb5996 100644
--- a/lib/Db/CardMapper.php
+++ b/lib/Db/CardMapper.php
@@ -23,6 +23,7 @@
 
 namespace OCA\Deck\Db;
 
+use OC\Notification\Notification;
 use OCP\AppFramework\Db\Entity;
 use OCP\IDBConnection;
 use OCP\IUserManager;