diff --git a/.gitmodules b/.gitmodules
index c3d4d7c8..b9fac3e3 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -16,3 +16,6 @@
 [submodule "ref/glfw"]
 	path = ref/glfw
 	url = https://github.com/glfw/glfw
+[submodule "ref/asio"]
+	path = ref/asio
+	url = https://github.com/chriskohlhoff/asio.git
diff --git a/ref/asio b/ref/asio
new file mode 160000
index 00000000..4730c543
--- /dev/null
+++ b/ref/asio
@@ -0,0 +1 @@
+Subproject commit 4730c543ba2b8f9396ef1964a25ccc26eb1aea64