diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..032a3fa
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "lwip"]
+	path = lwip
+	url = https://github.com/lwip-tcpip/lwip
diff --git a/lwip b/lwip
new file mode 160000
index 0000000..73fcf72
--- /dev/null
+++ b/lwip
@@ -0,0 +1 @@
+Subproject commit 73fcf72792a926a4e0ac8b656b29bff70552d927