diff --git a/docs/requirements.txt b/docs/requirements.txt
index 6ac611d..81ca5c8 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,3 @@
-sphinx           == 7.3.7
+sphinx           == 7.1.2 # this is the last version that supports Python 3.8
 sphinx_rtd_theme == 2.0.0
 sphinx-computron >= 0.2, < 2.0