diff --git a/db/db.go b/db/db.go
index 13b6ca3..66c2ac5 100644
--- a/db/db.go
+++ b/db/db.go
@@ -57,7 +57,7 @@ func AddUserInChat(chatID int64, username string) error {
 	_, err = collection.UpdateOne(
 		ctx,
 		bson.M{"chat_id": chatID},
-		bson.M{"addToSet": bson.M{"users": username}},
+		bson.M{"$addToSet": bson.M{"users": username}},
 	)
 	return err
 }