diff --git a/src/domain/session/room/RoomViewModel.js b/src/domain/session/room/RoomViewModel.js
index 1ad92dd5..b3fc703c 100644
--- a/src/domain/session/room/RoomViewModel.js
+++ b/src/domain/session/room/RoomViewModel.js
@@ -216,9 +216,9 @@ export class RoomViewModel extends ViewModel {
                        } catch (exc) {
                            if ((exc.statusCode ?? exc.status) === 400) {
                                this._sendError = new Error(`/join : '${roomName}' was not legal room ID or room alias`);
-                           } else if (exc.statusCode ?? exc.status) === 404 || (exc.statusCode ?? exc.status) === 502 || exc.message == "Internal Server Error") {
+                           } else if ((exc.statusCode ?? exc.status) === 404 || (exc.statusCode ?? exc.status) === 502 || exc.message == "Internal Server Error") {
                                this._sendError = new Error(`/join : room '${roomName}' not found`);
-                           } else if (exc.statusCode ?? exc.status) === 403) {
+                           } else if ((exc.statusCode ?? exc.status) === 403) {
                                this._sendError = new Error(`/join : you're not invited to join '${roomName}'`);
                            } else {
                                this._sendError = new Error("join syntax: /join <room-id>");