diff --git a/packages/backend/src/SocketIOConnection.ts b/packages/backend/src/SocketIOConnection.ts
index 5eec34a..aaad24e 100644
--- a/packages/backend/src/SocketIOConnection.ts
+++ b/packages/backend/src/SocketIOConnection.ts
@@ -219,6 +219,7 @@ export default class SocketIOCollaboration {
   garbageCursors = (nsp: string) => {
     const doc = this.backend.getDocument(nsp)
 
+    if (doc == null || doc == undefined) return;
     if (!doc.cursors) return
 
     const namespace = this.io.of(nsp)