diff --git a/pyproject.toml b/pyproject.toml
index 2642915..0dad646 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ dependencies = [
     "pydantic>=2.12.4",
     "requests>=2.32.5",
     "sphinx-rtd-theme>=3.0.2",
-    "sphinx<9",  # see https://github.com/executablebooks/MyST-Parser/issues/1077
+    "sphinx<10",  # see https://github.com/executablebooks/MyST-Parser/issues/1077
     "sphinxemoji>=0.3.1",
 ]