diff --git a/src/Http/Part.php b/src/Http/Part.php
index 4068a2e..1f5d5c1 100644
--- a/src/Http/Part.php
+++ b/src/Http/Part.php
@@ -45,6 +45,15 @@ class Part extends TreeRouteStack implements RouteInterface
      */
     protected $childRoutes;
 
+    /**
+     * Priority.
+     *
+     * @internal For internal classes only. Not designed for general use.
+     *
+     * @var int|null
+     */
+    public $priority;
+
     /**
      * Create a new part route.
      *