diff --git a/docs/requirements.txt b/docs/requirements.txt
index ff627c61c7..b38dbc34b7 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -10,3 +10,9 @@ six
 future
 # Old Sphinx requires an old Jinja2
 jinja2<3.1
+sphinxcontrib_applehelp<1.0.8
+sphinxcontrib_devhelp<1.0.6
+sphinxcontrib_htmlhelp<2.0.5
+sphinxcontrib_qthelp<1.0.7
+sphinxcontrib_serializinghtml<1.0.7
+alabaster<0.7.14