diff -ru 9libs-1.0/include/libc.h 9libs-1.0-fixed/include/libc.h
--- 9libs-1.0/include/libc.h	1998-11-10 22:35:27.000000000 +0000
+++ 9libs-1.0-fixed/include/libc.h	2011-10-02 13:27:38.000000000 +0100
@@ -57,14 +57,14 @@
 extern	int	fprint(int, char *, ...);
 extern	int	sprint(char *, char *, ...);
 extern	int	snprint(char *, int, char *, ...);
-extern	int	fmtinstall(int, int (*)(void *, Fconv *));
+extern	int	fmtinstall(int, int (*)(va_list, Fconv *));
 extern	void	strconv(char *, Fconv *);
 #if defined(PRINT_RUNES)
 extern	void	Strconv(Rune *, Fconv *);
 #endif
-extern	int	numbconv(void *, Fconv *);
+extern	int	numbconv(va_list, Fconv *);
 extern	int	fltconv(double, Fconv *);
-extern	char *	doprint(char *, char *, char *, void *);
+extern	char *	doprint(char *, char *, char *, va_list);
 
 /*
  * argument parsing - lifted from tcs
diff -ru 9libs-1.0/libplan9c/doprint.c 9libs-1.0-fixed/libplan9c/doprint.c
--- 9libs-1.0/libplan9c/doprint.c	1998-11-10 22:35:28.000000000 +0000
+++ 9libs-1.0-fixed/libplan9c/doprint.c	2011-10-02 13:30:25.000000000 +0100
@@ -73,12 +73,12 @@
 		0,	0,	0,	0,	0,	0,	0,	0,
 };
 
-static int (*fmtfns[16])(void *, Fconv *) = {
+static int (*fmtfns[16])(va_list, Fconv *) = {
 	numbconv,
 };
 
 int
-fmtinstall(int c, int (*f)(void *, Fconv *))
+fmtinstall(int c, int (*f)(va_list, Fconv *))
 {
 	int i;
 
@@ -95,9 +95,8 @@
 }
 
 char *
-doprint(char *s, char *es, char *format, void *argp)
+doprint(char *s, char *es, char *format, va_list ap)
 {
-	va_list ap = argp;
 	int c;
 	int percent = 0;
 	int dot = 0;
@@ -218,7 +217,6 @@
 				if (r < 0)
 					f.f3 |= ~r;
 				else {
-					ap += r;
 					s = f.out;
 					percent = 0;
 				}
@@ -287,13 +285,12 @@
 #endif
 
 int
-numbconv(void *o, Fconv *fp)
+numbconv(va_list ap, Fconv *fp)
 {
 	static char digits[16] = "0123456789abcdef";
 	char buf[80];	/* arbitrary limit. enough digits, but no limit on f2 */
 	char *s = buf+sizeof(buf)-1;
 	char sign = 0;
-	va_list ap = o;
 	int uc = 0;
 	unsigned long u;
 
@@ -362,5 +359,5 @@
 		break;
 	}
 	strconv(s, fp);
-	return ap-(va_list)o;
+	return 0;
 }
diff -ru 9libs-1.0/libplan9c/tdp.c 9libs-1.0-fixed/libplan9c/tdp.c
--- 9libs-1.0/libplan9c/tdp.c	1998-11-10 22:35:28.000000000 +0000
+++ 9libs-1.0-fixed/libplan9c/tdp.c	2011-10-02 13:31:58.000000000 +0100
@@ -122,27 +122,25 @@
 } Rectangle;
 
 int
-Pconv(void *v, Fconv *fp)
+Pconv(va_list ap, Fconv *fp)
 {
 	char str[50];
-	va_list ap = v;
 	Point *p = va_arg(ap, Point *);
 
 	sprint(str, "(%d,%d)", p->x, p->y);
 	strconv(str, fp);
-	return ap-(va_list)v;
+	return 0;
 }
 
 int
-Rconv(void *v, Fconv *fp)
+Rconv(va_list ap, Fconv *fp)
 {
 	char str[50];
-	va_list ap = v;
 	Rectangle *r = va_arg(ap, Rectangle *);
 
 	sprint(str, "(%P,%P)", &r->min, &r->max);
 	strconv(str, fp);
-	return ap-(va_list)v;
+	return 0;
 }
 
 int