diff --git a/requirements.txt b/requirements.txt
index 3d1ba7f64..d27c5f8a7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,3 +3,4 @@ mkdocs-jupyter
 mkdocs-git-revision-date-localized-plugin
 mkdocs-awesome-pages-plugin
 mkdocs-htmlproofer-plugin
+markdown<3.4