diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000000000000000000000000000000000000..41342f5abe278f3cc8c1a36f0504984c5f9e3b94
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "autosubst"]
+	path = autosubst
+	url = https://github.com/tebbi/autosubst.git
diff --git a/autosubst b/autosubst
new file mode 160000
index 0000000000000000000000000000000000000000..4f8dc59286388e169f5c47c4f224a284202e52e7
--- /dev/null
+++ b/autosubst
@@ -0,0 +1 @@
+Subproject commit 4f8dc59286388e169f5c47c4f224a284202e52e7