diff --git a/windows/wingss.c b/windows/wingss.c
index a16db031..6e97d2e3 100644
--- a/windows/wingss.c
+++ b/windows/wingss.c
@@ -2,7 +2,6 @@
 
 #include "putty.h"
 
-#define SECURITY_WIN32
 #include <security.h>
 
 #include "sshgss.h"