diff --git a/src/Workbench/Workbench.php b/src/Workbench/Workbench.php
index 2123eafc..853ab2ba 100644
--- a/src/Workbench/Workbench.php
+++ b/src/Workbench/Workbench.php
@@ -399,6 +399,7 @@ public static function flush(): void
     {
         static::$cachedConfiguration = null;
         static::$cachedUserModel = null;
+        static::$cachedNamespaces = [];
 
         static::$cachedCoreBindings = [
             'kernel' => [],