diff --git a/docs/requirements.txt b/docs/requirements.txt
index 8843364..c2feefa 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -7,8 +7,10 @@ mkdocs-material
 mkdocs-img2fig-plugin
 mike
 
-
+weasyprint==52.5
 mkdocs-with-pdf
+pango-1.0-0
+libpangocairo
 
 mkdocs-bootswatch