diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 000000000..d74a0699a
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "themes/vienna"]
+	path = themes/vienna
+	url = https://github.com/keichi/vienna
diff --git a/themes/vienna b/themes/vienna
new file mode 160000
index 000000000..890e97c5a
--- /dev/null
+++ b/themes/vienna
@@ -0,0 +1 @@
+Subproject commit 890e97c5a052984d04294862ac60c7e0bfc6a934