diff --git a/src/Core/Models/Domain/TreeNode.cs b/src/Core/Models/Domain/TreeNode.cs
index cd0be31d5..524b81e63 100644
--- a/src/Core/Models/Domain/TreeNode.cs
+++ b/src/Core/Models/Domain/TreeNode.cs
@@ -6,7 +6,7 @@ namespace Bit.Core.Models.Domain
     {
         public T Parent { get; set; }
         public T Node { get; set; }
-        public List<TreeNode<T>> Children { get; set; }
+        public List<TreeNode<T>> Children { get; set; } = new List<TreeNode<T>>();
 
         public TreeNode(T node, string name, T parent)
         {