parsing Chinese string starts with `<` raises ParserError

>>> from lxml.html import fromstring
>>> fromstring('<你')
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/lxml/html/__init__.py", line 634, in fromstring
    doc = document_fromstring(html, parser=parser, base_url=base_url, **kw)
  File "/usr/lib/python2.7/dist-packages/lxml/html/__init__.py", line 535, in document_fromstring
    "Document is empty")
ParserError: Document is empty

你 is a Chinese character, the unicode representation is: '\u4f60'

>>> from lxml.html import fromstring
>>> fromstring('<\u4f60')
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/lxml/html/__init__.py", line 634, in fromstring
    doc = document_fromstring(html, parser=parser, base_url=base_url, **kw)
  File "/usr/lib/python2.7/dist-packages/lxml/html/__init__.py", line 535, in document_fromstring
    "Document is empty")
ParserError: Document is empty

So it seems like the combination `<\u` is the issue.

Version Info:

Python : sys.version_info(major=2, minor=7, micro=6, releaselevel='final', serial=0)
lxml.etree : (3, 4, 0, 0)
libxml used : (2, 9, 0)
libxml compiled : (2, 9, 0)
libxslt used : (1, 1, 28)
libxslt compiled : (1, 1, 28)