diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..e367eb2
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "client/others/hmac"]
+	path = client/others/hmac
+	url = https://github.com/ogay/hmac.git