diff --git a/app/controller/cron.php b/app/controller/cron.php
index 48a900f4ddd02d0e6b3162f5a4152c63abe791ac..4591c050925c12bf4843fead1d3222aae391f0f8 100644
--- a/app/controller/cron.php
+++ b/app/controller/cron.php
@@ -22,6 +22,9 @@ class Cron extends Controller
     {
         // This method is used to generate a piplome. It might be called with an
         // id parameters, in which case we will ask to regenerate a specific piplome.
+        if (!$f3->exists('SESSION.user')) {
+            $f3->reroute('/login');
+        }
         $logger = new \Log("/piplome.log");
         $ids = array();
         $db = $f3->get('DB');
diff --git a/www/index.php b/www/index.php
index 3ad2db40981b6c6cf9705e577aff7f8c351e5f6b..33a865dbb21e2f4707c6d900bfc535731ed5a1c9 100644
--- a/www/index.php
+++ b/www/index.php
@@ -45,10 +45,10 @@ $f3->set('ONERROR', function ($f3) {
 
     // If neither error or message are set, define them
     if (!$f3->exists('SESSION.message')) {
-        $f3->push('SESSION.message', '');
+        $f3->push('SESSION.message', []);
     }
     if (!$f3->exists('SESSION.error')) {
-        $f3->push('SESSION.error', '');
+        $f3->push('SESSION.error', []);
     }
     $f3->get('container')['session']->set('csrf', $csrf);