#if defined (HAVE_WCTYPE_H) && defined (HAVE_WCHAR_H)
# include <wchar.h>
# include <wctype.h>
-# if defined (HAVE_MBSRTOWCS) /* system is supposed to support XPG5 */
+# if defined (HAVE_MBRTOWC) && defined (HAVE_MBSRTOWCS)
+ /* system is supposed to support XPG5 */
# define HANDLE_MULTIBYTE 1
# endif
#endif