diff --git a/src/lib3270++/private.h b/src/lib3270++/private.h
index 2d2174f..c8c57ba 100644
--- a/src/lib3270++/private.h
+++ b/src/lib3270++/private.h
@@ -42,7 +42,7 @@
 
 	#include <config.h>
 
-	#ifdef WIN32
+	#ifdef _WIN32
 		#include <winsock2.h>
 		#include <windows.h>
 		#include <ws2tcpip.h>
--
libgit2 0.21.2