diff --git a/docs/requirements.txt b/docs/requirements.txt
index 8f15ab0..64db65e 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,7 +1,7 @@
 ipython
 pygments >= 2.7.*
 pydata-sphinx-theme
-sphinx >= 6.*
+sphinx == 6.*
 pandas
 lxml
 numpy