diff --git a/doc/install-all-deps.sh b/doc/install-all-deps.sh
index 54485b3638..ab9d831646 100755
--- a/doc/install-all-deps.sh
+++ b/doc/install-all-deps.sh
@@ -9,7 +9,7 @@ echo ""
 # Install Sphinx and documentation tools first
 echo "=== Installing Sphinx and documentation tools ==="
 pip install --trusted-host pypi.org --trusted-host files.pythonhosted.org \
-    sphinx sphinx-rtd-theme sphinxcontrib-httpdomain sphinxcontrib-images sphinxemoji rich
+    sphinx sphinx-rtd-theme sphinxcontrib-httpdomain sphinxcontrib-images sphinxcontrib-spelling sphinxemoji rich
 
 # Install ALL standard PyPI dependencies from pyproject.toml
 # Excluding git-based dependencies which need special handling
diff --git a/doc/requirements.txt b/doc/requirements.txt
index f31a0cdf83..ac170ef42c 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,10 +1,11 @@
 -e ../
-sphinx==2.3.*
+sphinx
 sphinx-rtd-theme
 sphinxcontrib-httpdomain
 sphinxcontrib-images
-sphinxcontrib-spelling==4.*
+sphinxcontrib-spelling
 sphinxemoji
 pygments-markdown-lexer
+rich
 # See https://github.com/rfk/pyenchant/pull/130
 git+https://github.com/raphaelm/pyenchant.git@patch-1#egg=pyenchant