Fix https://github.com/xml4r/libxml-ruby/issues/19
Fix https://github.com/xml4r/libxml-ruby/issues/19

sferik/libxml-ruby,sferik/libxml-ruby,sferik/libxml-ruby,increments/libxml-ruby,sferik/libxml-ruby,increments/libxml-ruby,xml4r/libxml-ruby,xml4r/libxml-ruby,sferik/libxml-ruby,sferik/libxml-ruby,increments/libxml-ruby,xml4r/libxml-ruby