diff --git a/pyproject.toml b/pyproject.toml
index b5ceb26c7..bdf6c4bef 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,7 @@ dependencies = [
 [project.optional-dependencies]
 doc = [
     "numpydoc==1.5.0",
-    "Sphinx==6.2.1",
+    "Sphinx==6.2.1", # BLOCKED BY sphinx-design - Cannot upgrade to Sphinx 7 for now
     "sphinx-copybutton==0.5.2",
     "sphinx-notfound-page==0.8.3",
     "sphinx-design==0.4.1",