diff --git a/rfb_win32/SFileTransferWin32.h b/rfb_win32/SFileTransferWin32.h
index f4c87ea..5f682a4 100644
--- a/rfb_win32/SFileTransferWin32.h
+++ b/rfb_win32/SFileTransferWin32.h
@@ -38,7 +38,7 @@
     {
     public:
       SFileTransferWin32(network::Socket *sock);
-      ~SFileTransferWin32();
+      virtual ~SFileTransferWin32();
 
       bool processDownloadCallback();
       virtual bool initDownloadCallback();