diff --git a/spcd.sh b/spcd.sh
index d081c44..ef7fad4 100644
--- a/spcd.sh
+++ b/spcd.sh
@@ -713,7 +713,7 @@ index-url = ${SPCD_URL_PYTHON}
 	pip install \
 		"pelican" \
 		"ruff" \
-		"sphinx"
+		"sphinx" "sphinx-rtd-theme"
 }
 
 spcd_install_python_modules() {