yamllint: UnicodeDecodeError: 'ascii' codec can't decode byte

Checking YAML
Traceback (most recent call last):
  File "/usr/local/bin/yamllint", line 11, in <module>
    sys.exit(run())
  File "/usr/local/lib/python3.5/dist-packages/yamllint/cli.py", line 170, in run
    problems = linter.run(f, conf, filepath)
  File "/usr/local/lib/python3.5/dist-packages/yamllint/linter.py", line 233, in run
    content = input.read()
  File "/usr/lib/python3.5/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 28220: ordinal not in range(128)

LANG=C.UTF-8 yamllint file.yaml