diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index d6ef8414ee..0952a48c0b 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -458,9 +458,12 @@ static void print_object_or_die(struct batch_options *opt, struct expand_data *d
 static void print_default_format(struct strbuf *scratch, struct expand_data *data,
 				 struct batch_options *opt)
 {
-	strbuf_addf(scratch, "%s %s %"PRIuMAX"%c", oid_to_hex(&data->oid),
-		    type_name(data->type),
-		    (uintmax_t)data->size, opt->output_delim);
+	strbuf_add_oid_hex(scratch, &data->oid);
+	strbuf_addch(scratch, ' ');
+	strbuf_addstr(scratch, type_name(data->type));
+	strbuf_addch(scratch, ' ');
+	strbuf_add_uint(scratch, data->size);
+	strbuf_addch(scratch, opt->output_delim);
 }
 
 static void report_object_status(struct batch_options *opt,