diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..81b70e3
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "tests/bats-core"]
+	path = tests/bats-core
+	url = https://github.com/bats-core/bats-core.git
diff --git a/tests/bats-core b/tests/bats-core
new file mode 160000
index 0000000..8789f91
--- /dev/null
+++ b/tests/bats-core
@@ -0,0 +1 @@
+Subproject commit 8789f910812afbf6b87dd371ee5ae30592f1423f