diff --git a/Packages/net.fushizen.modular-avatar/Runtime/ModularAvatarMergeArmature.cs b/Packages/net.fushizen.modular-avatar/Runtime/ModularAvatarMergeArmature.cs
index 9066a158..39cb00b8 100644
--- a/Packages/net.fushizen.modular-avatar/Runtime/ModularAvatarMergeArmature.cs
+++ b/Packages/net.fushizen.modular-avatar/Runtime/ModularAvatarMergeArmature.cs
@@ -24,6 +24,9 @@
 
 using System.Collections.Generic;
 using UnityEngine;
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
 
 namespace net.fushizen.modular_avatar.core
 {