diff --git a/ci-dev/doc_requirements.txt b/ci-dev/doc_requirements.txt
index 0879e7a861..7a2c7f54f4 100644
--- a/ci-dev/doc_requirements.txt
+++ b/ci-dev/doc_requirements.txt
@@ -1,4 +1,4 @@
-sphinx==8.1.3
+sphinx==9.1.0
 pydata-sphinx-theme==0.16.1
 sphinx-design==0.7.0
 sphinx-gallery==0.20.0