diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..aa43d7c
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "pingjs"]
+	path = pingjs
+	url = https://github.com/jdfreder/pingjs.git
diff --git a/pingjs b/pingjs
new file mode 160000
index 0000000..c2190a3
--- /dev/null
+++ b/pingjs
@@ -0,0 +1 @@
+Subproject commit c2190a3649759f2bd8569a72ae2b597b2546c871