diff --git a/cmd/demo-signal-client/main.go b/cmd/demo-signal-client/main.go
index 6d810f4..728ab5c 100644
--- a/cmd/demo-signal-client/main.go
+++ b/cmd/demo-signal-client/main.go
@@ -97,9 +97,18 @@ Type a message and press Enter to send.`)
 	if err != nil {
 		panic(err)
 	}
+	port := parsedUrl.Port()
 	if parsedUrl.Scheme == "https" {
 		transportCredential = credentials.NewTLS(&tls.Config{})
 	}
+	if port == "" {
+		switch parsedUrl.Scheme {
+		case "https":
+			port = "443"
+		default:
+			port = "80"
+		}
+	}
 
 	client := &SignalClient{
 		UI: SignalClientUI{
@@ -115,7 +124,7 @@ Type a message and press Enter to send.`)
 			},
 		},
 
-		Server:     fmt.Sprintf("%v:%v", parsedUrl.Hostname(), parsedUrl.Port()),
+		Server:     fmt.Sprintf("%v:%v", parsedUrl.Hostname(), port),
 		Credential: transportCredential,
 
 		Room: room,