diff --git a/src/Models/InventoryCategory.php b/src/Models/InventoryCategory.php
index c44ba9aa..e1cb9aee 100644
--- a/src/Models/InventoryCategory.php
+++ b/src/Models/InventoryCategory.php
@@ -9,6 +9,9 @@ class InventoryCategory extends Node
 {
     use CategoryTrait;
 
+    protected $leftColumnName = 'lft';
+    protected $rightColumnName = 'rgt';
+
     protected $fillable = [
                 'name',
               ];