diff --git a/tox.ini b/tox.ini
index 48d0ff458..c84007afd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -137,7 +137,7 @@ commands =
 description = Build documentation
 deps =
   -rrequirements-dev.txt
-  sphinx
+  sphinx!=5.1.0
   sphinx-rtd-theme
 changedir = {toxinidir}/docs
 whitelist_externals =