diff --git a/dlls/system.drv16/system.c b/dlls/system.drv16/system.c
index 83c0c87ec06..8bb5cf910df 100644
--- a/dlls/system.drv16/system.c
+++ b/dlls/system.drv16/system.c
@@ -18,10 +18,10 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
-#define NONAMELESSUNION
-#define NONAMELESSSTRUCT
 #include <stdarg.h>
 
+#define NONAMELESSUNION
+
 #include "windef.h"
 #include "winbase.h"
 #include "wine/winbase16.h"