diff --git a/README.md b/README.md
index 526bb43..b22026b 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ var (
 )
 
 func main() {
+	flag.Parse()
 	u, err := url.Parse(*flagBackend)
 	if err != nil {
 		log.Fatalln(err)
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..fc13b5a
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,5 @@
+module github.com/koding/websocketproxy
+
+go 1.16
+
+require github.com/gorilla/websocket v1.5.0
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..e5a03d4
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc=
+github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=