diff --git a/builtins/printf.def b/builtins/printf.def
index 71a7c00..94e5af5 100644
--- a/builtins/printf.def
+++ b/builtins/printf.def
@@ -471,6 +471,11 @@ printf_builtin (list)
 		sv_tz ("TZ");		/* XXX -- just make sure */
 #endif
 		tm = localtime (&secs);
+        if (tm == NULL)
+          {
+            secs = 0;
+            tm = localtime (&secs);
+          }
 		n = strftime (timebuf, sizeof (timebuf), timefmt, tm);
 		free (timefmt);
 		if (n == 0)