diff --git a/printf.c b/printf.c
index f94dc5e..6d7953d 100644
--- a/printf.c
+++ b/printf.c
@@ -196,6 +196,7 @@ static int getint(char **s) {
 static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg, int *nl_type)
 {
   char *a, *z, *s=(char *)fmt;
+  char buf[32];
   unsigned l10n=0, fl;
   int w, p, xp;
   union arg arg;
@@ -291,6 +292,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
 
     if (!f) continue;
 
+    z = buf + sizeof(buf);
     prefix = "-+   0X0x";
     pl = 0;
     t = s[-1];