diff --git a/include/stdarg.h b/include/stdarg.h
index 638f71d0..6a8fee6a 100644
--- a/include/stdarg.h
+++ b/include/stdarg.h
@@ -23,6 +23,9 @@
 #if SYSTEM_LIBC
 #undef __MES_STDARG_H
 #include_next <stdarg.h>
+
+#define va_arg8(ap, type) va_arg(ap, type)
+
 #else // ! SYSTEM_LIBC
 
 #include <sys/types.h>