diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5625059f9..ba7350885 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -593,6 +593,7 @@ set(TDLIB_SOURCE
   td/telegram/SecretChatActor.h
   td/telegram/SecretChatId.h
   td/telegram/SecretChatDb.h
+  td/telegram/SecretChatLayer.h
   td/telegram/SecretChatsManager.h
   td/telegram/SecretInputMedia.h
   td/telegram/SecureManager.h
diff --git a/td/telegram/ContactsManager.cpp b/td/telegram/ContactsManager.cpp
index 8c887e680..892a7cd29 100644
--- a/td/telegram/ContactsManager.cpp
+++ b/td/telegram/ContactsManager.cpp
@@ -36,7 +36,7 @@
 #include "td/telegram/PasswordManager.h"
 #include "td/telegram/Photo.h"
 #include "td/telegram/Photo.hpp"
-#include "td/telegram/SecretChatActor.h"
+#include "td/telegram/SecretChatLayer.h"
 #include "td/telegram/SecretChatsManager.h"
 #include "td/telegram/ServerMessageId.h"
 #include "td/telegram/StickerSetId.hpp"
@@ -4459,7 +4459,7 @@ void ContactsManager::ChannelFull::parse(ParserT &parser) {
 template <class StorerT>
 void ContactsManager::SecretChat::store(StorerT &storer) const {
   using td::store;
-  bool has_layer = layer > SecretChatActor::DEFAULT_LAYER;
+  bool has_layer = layer > static_cast<int32>(SecretChatLayer::DEFAULT_LAYER);
   bool has_initial_folder_id = initial_folder_id != FolderId();
   BEGIN_STORE_FLAGS();
   STORE_FLAG(is_outbound);
@@ -4505,7 +4505,7 @@ void ContactsManager::SecretChat::parse(ParserT &parser) {
   if (has_layer) {
     parse(layer, parser);
   } else {
-    layer = SecretChatActor::DEFAULT_LAYER;
+    layer = static_cast<int32>(SecretChatLayer::DEFAULT_LAYER);
   }
   if (has_initial_folder_id) {
     parse(initial_folder_id, parser);
diff --git a/td/telegram/MessageEntity.cpp b/td/telegram/MessageEntity.cpp
index c67679e3b..100b272cd 100644
--- a/td/telegram/MessageEntity.cpp
+++ b/td/telegram/MessageEntity.cpp
@@ -10,7 +10,7 @@
 #include "td/telegram/Dependencies.h"
 #include "td/telegram/LinkManager.h"
 #include "td/telegram/misc.h"
-#include "td/telegram/SecretChatActor.h"
+#include "td/telegram/SecretChatLayer.h"
 
 #include "td/utils/algorithm.h"
 #include "td/utils/format.h"
@@ -2992,17 +2992,17 @@ vector<tl_object_ptr<secret_api::MessageEntity>> get_input_secret_message_entiti
         result.push_back(make_tl_object<secret_api::messageEntityItalic>(entity.offset, entity.length));
         break;
       case MessageEntity::Type::Underline:
-        if (layer >= SecretChatActor::NEW_ENTITIES_LAYER) {
+        if (layer >= static_cast<int32>(SecretChatLayer::NEW_ENTITIES_LAYER)) {
           result.push_back(make_tl_object<secret_api::messageEntityUnderline>(entity.offset, entity.length));
         }
         break;
       case MessageEntity::Type::Strikethrough:
-        if (layer >= SecretChatActor::NEW_ENTITIES_LAYER) {
+        if (layer >= static_cast<int32>(SecretChatLayer::NEW_ENTITIES_LAYER)) {
           result.push_back(make_tl_object<secret_api::messageEntityStrike>(entity.offset, entity.length));
         }
         break;
       case MessageEntity::Type::BlockQuote:
-        if (layer >= SecretChatActor::NEW_ENTITIES_LAYER) {
+        if (layer >= static_cast<int32>(SecretChatLayer::NEW_ENTITIES_LAYER)) {
           result.push_back(make_tl_object<secret_api::messageEntityBlockquote>(entity.offset, entity.length));
         }
         break;
diff --git a/td/telegram/SecretChatActor.cpp b/td/telegram/SecretChatActor.cpp
index 7aad834c4..032e51dd6 100644
--- a/td/telegram/SecretChatActor.cpp
+++ b/td/telegram/SecretChatActor.cpp
@@ -440,8 +440,9 @@ void SecretChatActor::binlog_replay_finish() {
   LOG(INFO) << "Binlog replay is finished with PfsState " << pfs_state_;
   binlog_replay_finish_flag_ = true;
   if (auth_state_.state == State::Ready) {
-    if (config_state_.my_layer < MY_LAYER) {
-      send_action(secret_api::make_object<secret_api::decryptedMessageActionNotifyLayer>(MY_LAYER), SendFlag::None,
+    auto my_layer = static_cast<int32>(SecretChatLayer::MY_LAYER);
+    if (config_state_.my_layer < my_layer) {
+      send_action(secret_api::make_object<secret_api::decryptedMessageActionNotifyLayer>(my_layer), SendFlag::None,
                   Promise<>());
     }
   }
@@ -845,7 +846,8 @@ Status SecretChatActor::do_inbound_message_encrypted(unique_ptr<log_event::Inbou
     parser.fetch_end();
     if (!parser.get_error()) {
       auto layer = message_with_layer->layer_;
-      if (layer < DEFAULT_LAYER && false /* old Android app could send such messages */) {
+      if (layer < static_cast<int32>(SecretChatLayer::DEFAULT_LAYER) &&
+          false /* old Android app could send such messages */) {
         LOG(ERROR) << "Layer " << layer << " is not supported, drop message " << to_string(message_with_layer);
         return Status::OK();
       }
@@ -854,7 +856,7 @@ Status SecretChatActor::do_inbound_message_encrypted(unique_ptr<log_event::Inbou
         context_->secret_chat_db()->set_value(config_state_);
         send_update_secret_chat();
       }
-      if (layer >= MTPROTO_2_LAYER && mtproto_version < 2) {
+      if (layer >= static_cast<int32>(SecretChatLayer::MTPROTO_2_LAYER) && mtproto_version < 2) {
         return Status::Error(PSLICE() << "MTProto 1.0 encryption is forbidden for this layer");
       }
       if (message_with_layer->in_seq_no_ < 0) {
@@ -871,8 +873,9 @@ Status SecretChatActor::do_inbound_message_encrypted(unique_ptr<log_event::Inbou
 
   // support for older layer
   LOG(WARNING) << "Failed to fetch update: " << status;
-  send_action(secret_api::make_object<secret_api::decryptedMessageActionNotifyLayer>(MY_LAYER), SendFlag::None,
-              Promise<>());
+  send_action(secret_api::make_object<secret_api::decryptedMessageActionNotifyLayer>(
+                  static_cast<int32>(SecretChatLayer::MY_LAYER)),
+              SendFlag::None, Promise<>());
 
   if (config_state_.his_layer == 8) {
     TlBufferParser new_parser(&data_buffer);
@@ -1844,8 +1847,9 @@ Status SecretChatActor::on_update_chat(telegram_api::encryptedChat &update) {
   context_->secret_chat_db()->set_value(pfs_state_);
   context_->secret_chat_db()->set_value(auth_state_);
   send_update_secret_chat();
-  send_action(secret_api::make_object<secret_api::decryptedMessageActionNotifyLayer>(MY_LAYER), SendFlag::None,
-              Promise<>());
+  send_action(secret_api::make_object<secret_api::decryptedMessageActionNotifyLayer>(
+                  static_cast<int32>(SecretChatLayer::MY_LAYER)),
+              SendFlag::None, Promise<>());
   return Status::OK();
 }
 Status SecretChatActor::on_update_chat(telegram_api::encryptedChatDiscarded &update) {
diff --git a/td/telegram/SecretChatActor.h b/td/telegram/SecretChatActor.h
index 4726bb540..97a33d852 100644
--- a/td/telegram/SecretChatActor.h
+++ b/td/telegram/SecretChatActor.h
@@ -14,6 +14,7 @@
 #include "td/telegram/secret_api.h"
 #include "td/telegram/SecretChatDb.h"
 #include "td/telegram/SecretChatId.h"
+#include "td/telegram/SecretChatLayer.h"
 #include "td/telegram/telegram_api.h"
 #include "td/telegram/UserId.h"
 
@@ -48,14 +49,6 @@ class NetQueryCreator;
 
 class SecretChatActor final : public NetQueryCallback {
  public:
-  enum : int32 {
-    DEFAULT_LAYER = 73,
-    MTPROTO_2_LAYER = 73,
-    NEW_ENTITIES_LAYER = 101,
-    DELETE_MESSAGES_ON_CLOSE_LAYER = 123,
-    MY_LAYER = DELETE_MESSAGES_ON_CLOSE_LAYER
-  };
-
   class Context {
    public:
     Context() = default;
@@ -646,12 +639,12 @@ class SecretChatActor final : public NetQueryCallback {
   Status save_common_info(T &update);
 
   int32 current_layer() const {
-    int32 layer = MY_LAYER;
+    int32 layer = static_cast<int32>(SecretChatLayer::MY_LAYER);
     if (config_state_.his_layer < layer) {
       layer = config_state_.his_layer;
     }
-    if (layer < DEFAULT_LAYER) {
-      layer = DEFAULT_LAYER;
+    if (layer < static_cast<int32>(SecretChatLayer::DEFAULT_LAYER)) {
+      layer = static_cast<int32>(SecretChatLayer::DEFAULT_LAYER);
     }
     return layer;
   }
diff --git a/td/telegram/SecretChatLayer.h b/td/telegram/SecretChatLayer.h
new file mode 100644
index 000000000..ff1aa770e
--- /dev/null
+++ b/td/telegram/SecretChatLayer.h
@@ -0,0 +1,19 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2021
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+#pragma once
+
+namespace td {
+
+enum class SecretChatLayer : int32 {
+  DEFAULT_LAYER = 73,
+  MTPROTO_2_LAYER = 73,
+  NEW_ENTITIES_LAYER = 101,
+  DELETE_MESSAGES_ON_CLOSE_LAYER = 123,
+  MY_LAYER = DELETE_MESSAGES_ON_CLOSE_LAYER
+};
+
+}  // namespace td