diff --git a/.gitmodules b/.gitmodules
index 737f4d6..b45eb46 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "vendor/shunit2"]
 	path = vendor/shunit2
 	url = https://github.com/kward/shunit2
+[submodule "vendor/stub.sh"]
+	path = vendor/stub.sh
+	url = https://github.com/ericfreese/stub.sh
diff --git a/vendor/stub.sh b/vendor/stub.sh
new file mode 160000
index 0000000..bd6f3c4
--- /dev/null
+++ b/vendor/stub.sh
@@ -0,0 +1 @@
+Subproject commit bd6f3c4666cd2a702e388e09d77b8543a1f6b672