diff --git a/tox.ini b/tox.ini
index df501d3..85fcaf6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -45,6 +45,7 @@ deps =
   psycopg2-binary<2.9
   oldldap: python-ldap<3
   ldaptools
+  Markdown<3
 
   # pytest requirements
   pytest