diff --git a/td/telegram/DialogParticipant.h b/td/telegram/DialogParticipant.h
index 393048d8e..937cf1d41 100644
--- a/td/telegram/DialogParticipant.h
+++ b/td/telegram/DialogParticipant.h
@@ -497,16 +497,13 @@ class ChannelParticipantsFilter {
 StringBuilder &operator<<(StringBuilder &string_builder, const ChannelParticipantsFilter &filter);
 
 class DialogParticipantsFilter {
-  MessageId top_thread_message_id_;
-
- public:
   enum class Type : int32 { Contacts, Administrators, Members, Restricted, Banned, Mention, Bots };
   Type type_;
+  MessageId top_thread_message_id_;
 
-  explicit DialogParticipantsFilter(Type type, MessageId top_thread_message_id = MessageId())
-      : type_(type), top_thread_message_id_(top_thread_message_id) {
-  }
+  friend StringBuilder &operator<<(StringBuilder &string_builder, const DialogParticipantsFilter &filter);
 
+ public:
   explicit DialogParticipantsFilter(const tl_object_ptr<td_api::ChatMembersFilter> &filter);
 
   td_api::object_ptr<td_api::SupergroupMembersFilter> get_supergroup_members_filter_object(const string &query) const;
diff --git a/td/telegram/GroupCallManager.cpp b/td/telegram/GroupCallManager.cpp
index 2a4a590db..c088184f3 100644
--- a/td/telegram/GroupCallManager.cpp
+++ b/td/telegram/GroupCallManager.cpp
@@ -2661,8 +2661,8 @@ void GroupCallManager::try_load_group_call_administrators(InputGroupCallId input
                      std::move(result));
       });
   td_->contacts_manager_->search_dialog_participants(
-      dialog_id, string(), 100, DialogParticipantsFilter(DialogParticipantsFilter::Type::Administrators),
-      std::move(promise));
+      dialog_id, string(), 100,
+      DialogParticipantsFilter(td_api::make_object<td_api::chatMembersFilterAdministrators>()), std::move(promise));
 }
 
 void GroupCallManager::finish_load_group_call_administrators(InputGroupCallId input_group_call_id,