diff --git a/requirements-doc.txt b/requirements-doc.txt
index 453a5c79..a2bb3511 100644
--- a/requirements-doc.txt
+++ b/requirements-doc.txt
@@ -6,7 +6,7 @@ numba
 # document requirements
 pandoc
 Jinja2
-sphinx>=5, <8.2.0
+sphinx>=5, <9.1.0
 myst-nb
 sphinx_thebe
 sphinx-autodoc-typehints