diff --git a/tox.ini b/tox.ini
index 11f5ad2d1..eaf0a4360 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,7 +33,7 @@ commands = flake8 src/ test/
 
 [testenv:docs]
 deps =
-    sphinx>=4.0.2,<5
+    sphinx>=5.0.2,<6
 allowlist_externals = make
 changedir = {toxinidir}/docs
 commands =