diff --git a/src/main.js b/src/main.js
index 0225cb79..d24b03b3 100644
--- a/src/main.js
+++ b/src/main.js
@@ -218,7 +218,7 @@ const mixin = {
         },
         getUnauthenticatedChannels() {
             const localSubscriptions = this.getLocalSubscriptions();
-            return localSubscriptions.join(",");
+            return localSubscriptions != null ? localSubscriptions.join(",") : "";
         },
         download(text, filename) {
             var element = document.createElement("a");