diff --git a/src/script/lua_api/l_async_events.h b/src/script/lua_api/l_async_events.h
index 3364bac6e..c33f3a962 100644
--- a/src/script/lua_api/l_async_events.h
+++ b/src/script/lua_api/l_async_events.h
@@ -23,7 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <vector>
 #include <map>
 
-#ifndef _MSC_VER
+#ifndef _WIN32
 #include <unistd.h>
 #else
 #define _WINSOCKAPI_