diff --git a/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php b/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php
index 1385a8ba409d2..d08d382e42c83 100644
--- a/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php
+++ b/src/Symfony/Component/Security/Core/Authentication/Token/AbstractToken.php
@@ -48,7 +48,7 @@ public function getRoleNames(): array
 
     public function getUserIdentifier(): string
     {
-        return $this->user->getUserIdentifier();
+        return $this->user ? $this->user->getUserIdentifier() : '';
     }
 
     /**