diff --git a/apps/comments/appinfo/routes.php b/apps/comments/appinfo/routes.php
index ab751ddb2a..66b3abe61b 100644
--- a/apps/comments/appinfo/routes.php
+++ b/apps/comments/appinfo/routes.php
@@ -20,9 +20,8 @@
  *
  */
 
-use \OCA\Comments\AppInfo\Application;
-
-$application = new Application();
-$application->registerRoutes($this, ['routes' => [
-	['name' => 'Notifications#view', 'url' => '/notifications/view/{id}', 'verb' => 'GET'],
-]]);
+return [
+	'routes' => [
+		['name' => 'Notifications#view', 'url' => '/notifications/view/{id}', 'verb' => 'GET'],
+	]
+];
diff --git a/apps/comments/lib/Activity/Listener.php b/apps/comments/lib/Activity/Listener.php
index 16852296cf..94176921f0 100644
--- a/apps/comments/lib/Activity/Listener.php
+++ b/apps/comments/lib/Activity/Listener.php
@@ -84,7 +84,7 @@ class Listener {
 
 		// Get all mount point owners
 		$cache = $this->mountCollection->getMountCache();
-		$mounts = $cache->getMountsForFileId($event->getComment()->getObjectId());
+		$mounts = $cache->getMountsForFileId((int)$event->getComment()->getObjectId());
 		if (empty($mounts)) {
 			return;
 		}
@@ -93,7 +93,7 @@ class Listener {
 		foreach ($mounts as $mount) {
 			$owner = $mount->getUser()->getUID();
 			$ownerFolder = $this->rootFolder->getUserFolder($owner);
-			$nodes = $ownerFolder->getById($event->getComment()->getObjectId());
+			$nodes = $ownerFolder->getById((int)$event->getComment()->getObjectId());
 			if (!empty($nodes)) {
 				/** @var Node $node */
 				$node = array_shift($nodes);
diff --git a/apps/comments/lib/Activity/Provider.php b/apps/comments/lib/Activity/Provider.php
index 7bf686e796..ea4810f92e 100644
--- a/apps/comments/lib/Activity/Provider.php
+++ b/apps/comments/lib/Activity/Provider.php
@@ -147,7 +147,7 @@ class Provider implements IProvider {
 						trim($subjectParameters[1], '/'),
 					]))
 					->setRichSubject($this->l->t('You commented on {file}'), [
-						'file' => $this->generateFileParameter($event->getObjectId(), $subjectParameters[1]),
+						'file' => $this->generateFileParameter((int)$event->getObjectId(), $subjectParameters[1]),
 					]);
 			} else {
 				$author = $this->generateUserParameter($subjectParameters[0]);
@@ -157,7 +157,7 @@ class Provider implements IProvider {
 					]))
 					->setRichSubject($this->l->t('{author} commented on {file}'), [
 						'author' => $author,
-						'file' => $this->generateFileParameter($event->getObjectId(), $subjectParameters[1]),
+						'file' => $this->generateFileParameter((int)$event->getObjectId(), $subjectParameters[1]),
 					]);
 			}
 		} else {
@@ -173,7 +173,7 @@ class Provider implements IProvider {
 	protected function parseMessage(IEvent $event) {
 		$messageParameters = $event->getMessageParameters();
 		try {
-			$comment = $this->commentsManager->get((int) $messageParameters[0]);
+			$comment = $this->commentsManager->get((string) $messageParameters[0]);
 			$message = $comment->getMessage();
 			$message = str_replace("\n", '<br />', str_replace(['<', '>'], ['&lt;', '&gt;'], $message));
 
diff --git a/apps/comments/lib/Controller/Notifications.php b/apps/comments/lib/Controller/Notifications.php
index c2a8175d17..9a07e2fbad 100644
--- a/apps/comments/lib/Controller/Notifications.php
+++ b/apps/comments/lib/Controller/Notifications.php
@@ -96,7 +96,7 @@ class Notifications extends Controller {
 			if($comment->getObjectType() !== 'files') {
 				return new NotFoundResponse();
 			}
-			$files = $this->folder->getById($comment->getObjectId());
+			$files = $this->folder->getById((int)$comment->getObjectId());
 			if(count($files) === 0) {
 				$this->markProcessed($comment);
 				return new NotFoundResponse();
diff --git a/apps/comments/lib/Notification/Notifier.php b/apps/comments/lib/Notification/Notifier.php
index 09092da539..60dd85f74c 100644
--- a/apps/comments/lib/Notification/Notifier.php
+++ b/apps/comments/lib/Notification/Notifier.php
@@ -94,7 +94,7 @@ class Notifier implements INotifier {
 					throw new \InvalidArgumentException('Unsupported comment object');
 				}
 				$userFolder = $this->rootFolder->getUserFolder($notification->getUser());
-				$nodes = $userFolder->getById($parameters[1]);
+				$nodes = $userFolder->getById((int)$parameters[1]);
 				if(empty($nodes)) {
 					throw new \InvalidArgumentException('Cannot resolve file id to Node instance');
 				}