diff --git a/crypto777/iguana_OS.c b/crypto777/iguana_OS.c
index 9b218f130..1d31c269e 100755
--- a/crypto777/iguana_OS.c
+++ b/crypto777/iguana_OS.c
@@ -30,7 +30,7 @@
 
 char *OS_mvstr()
 {
-#ifdef __WIN32
+#ifdef _WIN32
     return("rename");
 #else
     return("mv");