diff --git a/Src/Mark/MarkComponent.cs b/Src/Mark/MarkComponent.cs
index 41ebf94..5936f34 100644
--- a/Src/Mark/MarkComponent.cs
+++ b/Src/Mark/MarkComponent.cs
@@ -4,7 +4,6 @@ using System.Collections.Generic;
 using BITKit;
 using BITKit.WorldNode;
 using Unity.Mathematics;
-using UnityEngine;
 
 namespace Net.Project.B.Mark
 {
@@ -16,7 +15,7 @@ namespace Net.Project.B.Mark
     public class NameMark:IWorldNode
     {
         #if UNITY_5_3_OR_NEWER
-        [SerializeReference, SubclassSelector] private IReference name;
+        [UnityEngine.SerializeReference, SubclassSelector] private IReference name;
         public string Name => name?.Value;
 #endif
     }
diff --git a/Src/WorldNode/UnityLootContainerVisualNode.cs b/Src/WorldNode/UnityLootContainerVisualNode.cs
index 3ab6291..160c17c 100644
--- a/Src/WorldNode/UnityLootContainerVisualNode.cs
+++ b/Src/WorldNode/UnityLootContainerVisualNode.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using BITKit.WorldNode;
+#if UNITY_5_3_OR_NEWER
 using UnityEngine;
 
 namespace Net.Project.B.WorldNode
@@ -15,4 +16,5 @@ namespace Net.Project.B.WorldNode
     public Vector3 emptyJointEuler;
     public Transform visualModel;
     }
-}
\ No newline at end of file
+}
+#endif
\ No newline at end of file