UnicodeEncodeError when piping Unicode output

[macro]

Terminal supports UTF-8:

$ echo $LANG
en_US.UTF-8

Printing to stdout is OK:

$ python -mhttpie GET news.ycombinator.org  --pretty 
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
Cache-Control: private
Connection: close
Cache-Control: max-age=0
<snip/>

Piping Unicode output to a pager (or anything else reading from stdin) results in UnicodeEncodeError

$ python -mhttpie GET news.ycombinator.org  --pretty | less
Traceback (most recent call last):
  File "/opt/local/lib/python3.2/runpy.py", line 160, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/opt/local/lib/python3.2/runpy.py", line 73, in _run_code
    exec(code, run_globals)
  File "/opt/src/httpie/httpie/__main__.py", line 193, in <module>
    main()
  File "/opt/src/httpie/httpie/__main__.py", line 187, in main
    with_body=cli.OUT_RESPONSE_BODY in args.output_options
UnicodeEncodeError: 'ascii' codec can't encode character '\u2013' in position 13305: ordinal not in range(128)