diff --git a/include/_PDCLIB_config.h b/include/_PDCLIB_config.h
index f1d1475..f521260 100644
--- a/include/_PDCLIB_config.h
+++ b/include/_PDCLIB_config.h
@@ -216,11 +216,15 @@ struct _PDCLIB_imaxdiv_t
 /* Internal helper macro. va_round is not part of <stdarg.h>. */
 #define _PDCLIB_va_round( type ) ( (sizeof(type) + sizeof(void *) - 1) & ~(sizeof(void *) - 1) )
 
-typedef char * _PDCLIB_va_list;
-#define _PDCLIB_va_arg( ap, type ) ( (ap) += (_PDCLIB_va_round(type)), ( *(type*) ( (ap) - (_PDCLIB_va_round(type)) ) ) )
-#define _PDCLIB_va_copy( dest, src ) ( (dest) = (src), (void)0 )
-#define _PDCLIB_va_end( ap ) ( (ap) = (void *)0, (void)0 )
-#define _PDCLIB_va_start( ap, parmN ) ( (ap) = (char *) &parmN + ( _PDCLIB_va_round(parmN) ), (void)0 )
+/* arm-vita-eabi passes the first four words of a variadic call in
+   registers (AAPCS), so the stack-walking hack above -- which this file's
+   own comment already disclaims for non-stack-based architectures -- does
+   not locate them. Defer to the compiler's real va_list instead. */
+typedef __builtin_va_list _PDCLIB_va_list;
+#define _PDCLIB_va_arg( ap, type )    __builtin_va_arg( ap, type )
+#define _PDCLIB_va_copy( dest, src )  __builtin_va_copy( dest, src )
+#define _PDCLIB_va_end( ap )          __builtin_va_end( ap )
+#define _PDCLIB_va_start( ap, parmN ) __builtin_va_start( ap, parmN )
 
 /* -------------------------------------------------------------------------- */
 /* OS "glue", part 1                                                          */