diff --git a/.gitmodules b/.gitmodules
index fa048e0..73629a9 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "python/examples"]
 	path = python/examples
 	url = git@github.com:TREX-CoE/trexio-tutorials.git
+[submodule "docs/org-html-themes"]
+	path = docs/org-html-themes
+	url = git@github.com:fniessen/org-html-themes.git
diff --git a/docs/org-html-themes b/docs/org-html-themes
new file mode 160000
index 0000000..20f8418
--- /dev/null
+++ b/docs/org-html-themes
@@ -0,0 +1 @@
+Subproject commit 20f84182239a537f4c6b533eb65daa2d342428dd