diff --git a/DearFTP/FtpServer.cs b/DearFTP/FtpServer.cs
index 76f2658..c30c3ab 100644
--- a/DearFTP/FtpServer.cs
+++ b/DearFTP/FtpServer.cs
@@ -52,9 +52,10 @@ namespace DearFTP
         public void Stop()
         {
             _isRunning = false;
+            StaticDataConnection.Stop();
             _listener.Stop();
             _ftpsListener?.Stop();
-            StaticDataConnection.Stop();
+            Configuration.Tls.X509Certificate?.Dispose();
         }
 
         private void TcpLoop()