diff --git a/WelsonJS.Toolkit/WelsonJS.Launcher/ZipExtractor.cs b/WelsonJS.Toolkit/WelsonJS.Launcher/ZipExtractor.cs
index 8ea6610..d6c9691 100644
--- a/WelsonJS.Toolkit/WelsonJS.Launcher/ZipExtractor.cs
+++ b/WelsonJS.Toolkit/WelsonJS.Launcher/ZipExtractor.cs
@@ -4,7 +4,6 @@ using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
-using System.Security.Cryptography;
 using System.Threading.Tasks;
 
 namespace WelsonJS.Launcher