diff -up ppp-2.4.4/pppd/utils.c.varargs ppp-2.4.4/pppd/utils.c
--- ppp-2.4.4/pppd/utils.c.varargs	2004-11-04 05:02:26.000000000 -0500
+++ ppp-2.4.4/pppd/utils.c	2008-08-28 17:34:29.000000000 -0400
@@ -290,7 +290,7 @@ vslprintf(buf, buflen, fmt, args)
 #if 0	/* not used, and breaks on S/390, apparently */
 	case 'r':
 	    f = va_arg(args, char *);
-#ifndef __powerpc__
+#if !defined (__powerpc__) && !defined(__s390__) && !defined(__s390x__) && !defined(__x86_64__)
 	    n = vslprintf(buf, buflen + 1, f, va_arg(args, va_list));
 #else
 	    /* On the powerpc, a va_list is an array of 1 structure */