diff --git a/src/stores/RoomViewStore.js b/src/stores/RoomViewStore.js
index 5ddd84c07c..9e048e5d8e 100644
--- a/src/stores/RoomViewStore.js
+++ b/src/stores/RoomViewStore.js
@@ -224,6 +224,8 @@ class RoomViewStore extends Store {
                 err: err,
             });
             let msg = err.message ? err.message : JSON.stringify(err);
+            // XXX: We are relying on the error message returned by browsers here.
+            // This isn't great, but it does generalize the error being shown to users.
             if (msg && msg.startsWith("CORS request rejected")) {
                 msg = _t("There was an error joining the room");
             }