diff --git a/src/@types/global.d.ts b/src/@types/global.d.ts
index e719da92c2..5d72061be5 100644
--- a/src/@types/global.d.ts
+++ b/src/@types/global.d.ts
@@ -41,7 +41,7 @@ declare global {
         mxRebrandListener: RebrandListener;
         mxRoomListStore: RoomListStoreClass;
         mxRoomListLayoutStore: RoomListLayoutStore;
-        mx_ActiveRoomObserver: ActiveRoomObserver;
+        mxActiveRoomObserver: ActiveRoomObserver;
         mxPlatformPeg: PlatformPeg;
         mxIntegrationManagers: typeof IntegrationManagers;
         singletonModalManager: ModalManager;
diff --git a/src/ActiveRoomObserver.ts b/src/ActiveRoomObserver.ts
index 4ff4951915..cc3f29dc42 100644
--- a/src/ActiveRoomObserver.ts
+++ b/src/ActiveRoomObserver.ts
@@ -77,7 +77,7 @@ export class ActiveRoomObserver {
     };
 }
 
-if (window.mx_ActiveRoomObserver === undefined) {
-    window.mx_ActiveRoomObserver = new ActiveRoomObserver();
+if (window.mxActiveRoomObserver === undefined) {
+    window.mxActiveRoomObserver = new ActiveRoomObserver();
 }
-export default window.mx_ActiveRoomObserver;
+export default window.mxActiveRoomObserver;