diff --git a/requirements-dev.txt b/requirements-dev.txt
index d58218b..da4fe5b 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -112,7 +112,7 @@ sphinx-autodoc-typehints==3.0.1
     # via pyUSPTO (pyproject.toml)
 sphinx-copybutton==0.5.2
     # via pyUSPTO (pyproject.toml)
-sphinx-immaterial==0.13.8
+sphinx-immaterial==0.13.9
     # via pyUSPTO (pyproject.toml)
 sphinx-rtd-theme==3.1.0
     # via pyUSPTO (pyproject.toml)