diff --git a/docs/requirements.txt b/docs/requirements.txt
index 358ed0e..4a22701 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,3 @@
-sphinx>=2.0.0
+sphinx >=6.2.0, <7.0.0
 sphinx-rtd-theme>=0.4.3
 sphinxcontrib-plantuml>=0.15