diff --git a/core/modules/basic_auth/src/Authentication/Provider/BasicAuth.php b/core/modules/basic_auth/src/Authentication/Provider/BasicAuth.php
index 67d100f52c1..0e306a5b359 100644
--- a/core/modules/basic_auth/src/Authentication/Provider/BasicAuth.php
+++ b/core/modules/basic_auth/src/Authentication/Provider/BasicAuth.php
@@ -121,7 +121,7 @@ class BasicAuth implements AuthenticationProviderInterface, AuthenticationProvid
     }
     // Always register an IP-based failed login event.
     $this->flood->register('basic_auth.failed_login_ip', $flood_config->get('ip_window'));
-    return [];
+    return NULL;
   }
 
   /**