#!/usr/bin/perl
use warnings;
use strict;
use JSON::Parse ':all';
no utf8;
# 蟹
my $kani = '["\u87f9"]';
my $p = parse_json ($kani);
print "It's marked as a character string" if utf8::is_utf8 ($p->[0]);
# Prints "It's marked as a character string" because it's upgraded
# regardless of the input string's flags.