diff --git a/Scripts/Format/VRMImporter.cs b/Scripts/Format/VRMImporter.cs
index 34a86b32a..ee70dd364 100644
--- a/Scripts/Format/VRMImporter.cs
+++ b/Scripts/Format/VRMImporter.cs
@@ -6,7 +6,7 @@ using UniGLTF;
 using System.Collections.Generic;
 using System.Collections;
 using UniTask;
-#if (NET_4_6 && UNITY_2018_1_OR_NEWER)
+#if (NET_4_6 && UNITY_2017_1_OR_NEWER)
 using System.Threading.Tasks;
 #endif
 
@@ -485,7 +485,7 @@ namespace VRM
             yield return null;
         }
 
-#if (NET_4_6 && UNITY_2018_1_OR_NEWER)
+#if (NET_4_6 && UNITY_2017_1_OR_NEWER)
 
         public static Task<GameObject> LoadVrmAsync(string path)
         {
diff --git a/Scripts/UniTask/Schedulable.cs b/Scripts/UniTask/Schedulable.cs
index 3dab6552b..db8f498ec 100644
--- a/Scripts/UniTask/Schedulable.cs
+++ b/Scripts/UniTask/Schedulable.cs
@@ -1,7 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
-#if (NET_4_6 && UNITY_2018_1_OR_NEWER) 
+#if (NET_4_6 && UNITY_2017_1_OR_NEWER) 
 using System.Threading.Tasks;
 #endif
 
@@ -184,7 +184,7 @@ namespace UniTask
             TaskChain.Schedule(schedulable.GetRoot(), onError);
         }
 
-#if (NET_4_6 && UNITY_2018_1_OR_NEWER)
+#if (NET_4_6 && UNITY_2017_1_OR_NEWER)
         public static Task<T> ToTask<T>(this Schedulable<T> schedulable)
         {
             return ToTask(schedulable, Scheduler.MainThread);