diff --git a/docs/requirements.txt b/docs/requirements.txt
index d58ad498..c0a0c0bd 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,4 +1,4 @@
 m2r2>=0.3.4
-sphinx>=8,<9
+sphinx>=8.1.3,<9
 sphinx-autoapi>=3,<4
 sphinx-rtd-theme>=3,<4