diff --git a/ci-dev/doc_requirements.txt b/ci-dev/doc_requirements.txt
index 7be7fd459..fa1335d2f 100644
--- a/ci-dev/doc_requirements.txt
+++ b/ci-dev/doc_requirements.txt
@@ -1,7 +1,7 @@
 cartopy==0.25.0
 matplotlib==3.10.7
 metpy==1.7.1
-sphinx==8.2.3
+sphinx==9.0.0
 sphinx_rtd_theme==3.0.1
 sphinx-gallery==0.19.0
 myst-parser==4.0.1