diff --git a/telethon/telegram_client.py b/telethon/telegram_client.py
index 2c5bbaf2..68f5e810 100644
--- a/telethon/telegram_client.py
+++ b/telethon/telegram_client.py
@@ -1233,7 +1233,7 @@ class TelegramClient(TelegramBareClient):
                     if not participants.users:
                         requests.pop(i)
                     else:
-                        requests[i].offset += len(participants.users)
+                        requests[i].offset += len(participants.participants)
                         for user in participants.users:
                             if user.id not in seen:
                                 seen.add(user.id)