diff --git a/lib/Controller/UsersController.php b/lib/Controller/UsersController.php
index 9e13390..65bb69d 100644
--- a/lib/Controller/UsersController.php
+++ b/lib/Controller/UsersController.php
@@ -164,7 +164,7 @@ public function __construct($appName,
 
 	/**
 	 * @param IUser $user
-	 * @param array $userGroups
+	 * @param array|null $userGroups
 	 * @return array
 	 */
 	private function formatUserForIndex(IUser $user, array $userGroups = null) {
diff --git a/lib/Exception/UserTokenMismatchException.php b/lib/Exception/UserTokenMismatchException.php
index 71b683e..b85e9bc 100644
--- a/lib/Exception/UserTokenMismatchException.php
+++ b/lib/Exception/UserTokenMismatchException.php
@@ -23,7 +23,7 @@
 
 class UserTokenMismatchException extends UserTokenException {
 	public function __construct($message = "", $code = 0, \Exception $previous = null) {
-		$this->previousException = $this;
+		$this->previous = $this;
 		parent::__construct($message, $code, $previous);
 	}
 }
diff --git a/lib/MetaData.php b/lib/MetaData.php
index 9c49ae4..9e44d30 100644
--- a/lib/MetaData.php
+++ b/lib/MetaData.php
@@ -41,8 +41,8 @@ class MetaData {
 	protected $metaData = [];
 	/** @var \OCP\IGroupManager */
 	protected $groupManager;
-	/** @var bool */
-	protected $sorting = false;
+	/** @var int */
+	protected $sorting = self::SORT_NONE;
 	/** @var IUserSession */
 	protected $userSession;