diff --git a/comments.php b/comments.php
index 00b9790..b3823f1 100644
--- a/comments.php
+++ b/comments.php
@@ -174,10 +174,12 @@ class CommentsPlugin extends Plugin
                 $email = filter_var(urldecode($post['email']), FILTER_SANITIZE_STRING);
                 $title = filter_var(urldecode($post['title']), FILTER_SANITIZE_STRING);
 
-                $user = $this->grav['user'];
-                if ($user->authenticated) {
-                    $name = $user->fullname;
-                    $email = $user->email;
+                if (isset($this->grav['user'])) {
+                    $user = $this->grav['user'];
+                    if ($user->authenticated) {
+                        $name = $user->fullname;
+                        $email = $user->email;
+                    }
                 }
 
                 /** @var Language $language */