diff --git a/docs/requirements.txt b/docs/requirements.txt
index b8ab7b0f6..4b6f1de89 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -9,7 +9,7 @@ netCDF4
 # actual documentation requirements
 ipykernel
 nbsphinx
-sphinx<8
+sphinx<9
 sphinx-rtd-theme
 sphinx-design
 sphinx-gallery
diff --git a/pyproject.toml b/pyproject.toml
index bb1a5a086..386371418 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -195,7 +195,7 @@ test = [
 ]
 
 docs = [
-    "sphinx<8",
+    "sphinx<9",
     "nbsphinx",
     "sphinx-rtd-theme",
     "sphinx-design",