diff --git a/Security/AnonymousUser.php b/Security/AnonymousUser.php
index 70f1951..c5730e7 100644
--- a/Security/AnonymousUser.php
+++ b/Security/AnonymousUser.php
@@ -59,4 +59,12 @@ public function getUsername(): string
     public function eraseCredentials(): void
     {
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getUserIdentifier(): string
+    {
+        return $this->getUsername();
+    }
 }