diff --git a/lib/interfaces/rest.js b/lib/interfaces/rest.js
index 1d5e3fe83..e34773e47 100644
--- a/lib/interfaces/rest.js
+++ b/lib/interfaces/rest.js
@@ -72,7 +72,7 @@ module.exports = function(app) {
         }
 
         if (app.interfaces.tcp && app.interfaces.tcp.data) {
-          services['signalk-tcp'] = 'tcp://' + splitHost[0] + app.interfaces.tcp.data.port
+          services['signalk-tcp'] = `tcp://${splitHost[0]}:${app.interfaces.tcp.data.port}`
         }
 
         res.json({