diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..b7efcb4
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,9 @@
+[submodule "test/bats"]
+	path = test/bats
+	url = https://github.com/bats-core/bats-core.git
+[submodule "test/test_helper/bats-support"]
+	path = test/test_helper/bats-support
+	url = https://github.com/bats-core/bats-support.git
+[submodule "test/test_helper/bats-assert"]
+	path = test/test_helper/bats-assert
+	url = https://github.com/bats-core/bats-assert.git
diff --git a/test/bats b/test/bats
new file mode 160000
index 0000000..4417a96
--- /dev/null
+++ b/test/bats
@@ -0,0 +1 @@
+Subproject commit 4417a96cfc5e4afc493df94eeef8af4eec760163
diff --git a/test/test_helper/bats-assert b/test/test_helper/bats-assert
new file mode 160000
index 0000000..44913ff
--- /dev/null
+++ b/test/test_helper/bats-assert
@@ -0,0 +1 @@
+Subproject commit 44913ffe6020d1561c4c4d1e26cda8e07a1f374f
diff --git a/test/test_helper/bats-support b/test/test_helper/bats-support
new file mode 160000
index 0000000..3c8fadc
--- /dev/null
+++ b/test/test_helper/bats-support
@@ -0,0 +1 @@
+Subproject commit 3c8fadc5097c9acfc96d836dced2bb598e48b009