[lxml] Parsing HTML

Hi, I have a question about parsing HTML. >>> from lxml.html import fromstring, tostring It parses trailing whitespace in some cases: >>> html = """<div>some <i>text</i> </div>""" >>> html == tostring(fromstring(html)) True But it seems to break when encountering unknown tags (such as the "blah" tag below). >>> html = """<div>some <blah>text</blah> </div>""" >>> html == tostring(fromstring(html)) False How can I fix it to include trailing whitespace for all tags? Thanks, John.