diff --git a/school/lms/md.py b/school/lms/md.py
index b072af2a..5acb6322 100644
--- a/school/lms/md.py
+++ b/school/lms/md.py
@@ -105,7 +105,7 @@ def sanitize_html(html, macro):
     any broken tags. This makes sures that all those things are fixed
     before passing to the etree parser.
     """
-    soup = BeautifulSoup(html, features="html5lib")
+    soup = BeautifulSoup(html, features="lxml")
     nodes = soup.body.children
     classname = ""
     if macro == "YouTubeVideo":