diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index bc2319e..0cfc55a 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -20,8 +20,8 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install tox tox-gh-actions
-    - name: Build documentation with Sphinx 2.1
-      run: tox -e sphinx2.1
+    - name: Build documentation with Sphinx 2.4.5
+      run: tox -e sphinx2.4.5
     - name: Build documentation with latest Sphinx versions
       run: tox -e sphinx-latest
     - name: Static checks
diff --git a/tox.ini b/tox.ini
index d97d00b..20ba503 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,7 +2,7 @@
 envlist =
     check,
     py37, py38, py39, py310, py311, py312
-    sphinx2.1,
+    sphinx2.4.5,
     sphinx-latest,
 
 [gh-actions]
@@ -23,7 +23,7 @@ basepython =
     py310: {env:TOXPYTHON:python3.10}
     py311: {env:TOXPYTHON:python3.11}
     py312: {env:TOXPYTHON:python3.12}
-    {check,sphinx2.1,sphinx-latest}: python3
+    {check,sphinx2.4.5,sphinx-latest}: python3
 passenv =
     *
 usedevelop = true
@@ -46,13 +46,19 @@ commands =
     check-manifest {toxinidir} -u
     flake8 mlx setup.py
 
-[testenv:sphinx2.1]
+[testenv:sphinx2.4.5]
 deps=
     {[testenv]deps}
     jinja2 == 2.11.3
     markupsafe == 1.1.0
     docutils == 0.17
-    sphinx <= 2.1.9999
+    sphinx == 2.4.5
+    sphinxcontrib-applehelp<=1.0.4
+    sphinxcontrib-devhelp<=1.0.4
+    sphinxcontrib-htmlhelp<=2.0.4
+    sphinxcontrib-serializinghtml<=1.1.9
+    sphinxcontrib-qthelp<=1.0.6
+    alabaster<=0.7.13
     mlx.warnings >= 5.4.1
     sphinx_selective_exclude >= 1.0.3
 whitelist_externals =