decode_json() takes a binary encoded string

gistfile1.pl

#!/usr/bin/perl

use v5.14;
use warnings;
use utf8::all;
use Encode;
use Data::Dumper;
use JSON::XS qw( decode_json );

my $wl = '{"creche":"crèche", "¥":"£", "₡":"волн"}';
my $pattern_list = decode_json( encode("utf8", $wl) );

print Dumper $pattern_list;