diff --git a/apps/tasks/ajax/addtask.php b/apps/tasks/ajax/addtask.php
index 891fbdb96df69bca6c955ac1bff97696cf435769..d6e313bd089e44f691c032b2e003a66cd62f24ee 100644
--- a/apps/tasks/ajax/addtask.php
+++ b/apps/tasks/ajax/addtask.php
@@ -5,7 +5,8 @@ OCP\JSON::checkLoggedIn();
 OCP\JSON::checkAppEnabled('tasks');
 
 $calendars = OC_Calendar_Calendar::allCalendars(OCP\User::getUser(), true);
-$cid = reset($calendars)['id'];
+$first_calendar = reset($calendars);
+$cid = $first_calendar['id'];
 
 $input = $_GET['text'];
 $request = array();