diff --git a/pyproject.toml b/pyproject.toml
index 013b92a..96f7d9f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,7 @@ docs = [
     "matplotlib",
     "myst-parser",
     "nbsphinx",
-    "sphinx<9",
+    "sphinx<10",
     "sphinx-autobuild",
     "sphinx-click",
     "sphinx-copybutton",