diff --git a/docs/requirements.txt b/docs/requirements.txt
index 617d8d2f..3365c286 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,4 @@
+sphinx < 7
 sphinx-rtd-theme
 myst-parser
 tomli >= 1.1.0 ; python_version < "3.11"