diff --git a/spine-ue4/Plugins/SpinePlugin/Source/SpineEditorPlugin/SpineEditorPlugin.Build.cs b/spine-ue4/Plugins/SpinePlugin/Source/SpineEditorPlugin/SpineEditorPlugin.Build.cs
index 7ac952c63..36700343c 100644
--- a/spine-ue4/Plugins/SpinePlugin/Source/SpineEditorPlugin/SpineEditorPlugin.Build.cs
+++ b/spine-ue4/Plugins/SpinePlugin/Source/SpineEditorPlugin/SpineEditorPlugin.Build.cs
@@ -1,5 +1,8 @@
 // Copyright 1998-2016 Epic Games, Inc. All Rights Reserved.
 
+using System;
+using System.IO;
+
 namespace UnrealBuildTool.Rules
 {
 	public class SpineEditorPlugin : ModuleRules