diff --git a/arch/nt32/bits/stdarg.h b/arch/nt32/bits/stdarg.h
index 6b1830d..fde3781 100644
--- a/arch/nt32/bits/stdarg.h
+++ b/arch/nt32/bits/stdarg.h
@@ -1,9 +1,4 @@
-#define __VA_ALIGNED_SIZE(x) ((sizeof(x) + sizeof(int) - 1) & ~(sizeof(int) - 1))
-
-#define va_start(ap, last) ((ap) = (void *)(((char *)&(last)) + __VA_ALIGNED_SIZE(last)))
-#define va_end(ap) ((void)0)
-#define va_copy(dest, src) ((dest) = (src))
-
-#define va_arg(ap, type) \
-	( ((ap) = (va_list)((char *)(ap) + __VA_ALIGNED_SIZE(type))), \
-	*(type *)(void *)((char *)(ap) - __VA_ALIGNED_SIZE(type)) )
+#define va_start(v,l)   __builtin_va_start(v,l)
+#define va_end(v)       __builtin_va_end(v)
+#define va_arg(v,l)     __builtin_va_arg(v,l)
+#define va_copy(d,s)    __builtin_va_copy(d,s)