diff --git a/docs/.docs.requirements b/docs/.docs.requirements
index 97e2577..9a3e89a 100644
--- a/docs/.docs.requirements
+++ b/docs/.docs.requirements
@@ -1,6 +1,8 @@
 ipython
 furo
+lxml_html_clean
 m2r2
+matplotlib
 nbsphinx
 nbsphinx-link
 nbstripout