diff --git a/docs/requirements.txt b/docs/requirements.txt
index b528dfb..412cafc 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,5 +1,5 @@
 
 m2r2>=0.3.2
-sphinx>=7.2.6,<8
+sphinx>=7.2.6,<9
 sphinx-autoapi>=3.0.0,<4
 sphinx-rtd-theme>=2.0.0,<3