diff --git a/telegram-bot-api/Client.cpp b/telegram-bot-api/Client.cpp
index 192ae0b..fdfaf42 100644
--- a/telegram-bot-api/Client.cpp
+++ b/telegram-bot-api/Client.cpp
@@ -3194,6 +3194,55 @@ class Client::TdOnCheckMessageCallback final : public TdQueryCallback {
   OnSuccess on_success_;
 };
 
+template <class OnSuccess>
+class Client::TdOnCheckMessageThreadCallback final : public TdQueryCallback {
+ public:
+  TdOnCheckMessageThreadCallback(Client *client, int64 chat_id, int64 message_thread_id, int64 reply_to_message_id,
+                                 PromisedQueryPtr query, OnSuccess on_success)
+      : client_(client)
+      , chat_id_(chat_id)
+      , message_thread_id_(message_thread_id)
+      , reply_to_message_id_(reply_to_message_id)
+      , query_(std::move(query))
+      , on_success_(std::move(on_success)) {
+  }
+
+  void on_result(object_ptr<td_api::Object> result) final {
+    if (result->get_id() == td_api::error::ID) {
+      auto error = move_object_as<td_api::error>(result);
+      if (error->code_ == 429) {
+        LOG(WARNING) << "Failed to get message thread " << message_thread_id_ << " in " << chat_id_;
+      }
+      return fail_query_with_error(std::move(query_), std::move(error), "Message thread not found");
+    }
+
+    CHECK(result->get_id() == td_api::message::ID);
+    auto full_message_id = client_->add_message(move_object_as<td_api::message>(result));
+    CHECK(full_message_id.chat_id == chat_id_);
+    CHECK(full_message_id.message_id == message_thread_id_);
+
+    const MessageInfo *message_info = client_->get_message(chat_id_, message_thread_id_);
+    CHECK(message_info != nullptr);
+    if (message_info->message_thread_id != message_thread_id_) {
+      return fail_query_with_error(std::move(query_), 400, "MESSAGE_THREAD_INVALID", "Message thread not found");
+    }
+    if (!message_info->is_topic_message) {
+      return fail_query_with_error(std::move(query_), 400, "MESSAGE_THREAD_INVALID",
+                                   "Message thread is not a forum topic thread");
+    }
+
+    on_success_(chat_id_, message_thread_id_, reply_to_message_id_, std::move(query_));
+  }
+
+ private:
+  Client *client_;
+  int64 chat_id_;
+  int64 message_thread_id_;
+  int64 reply_to_message_id_;
+  PromisedQueryPtr query_;
+  OnSuccess on_success_;
+};
+
 template <class OnSuccess>
 class Client::TdOnCheckRemoteFileIdCallback final : public TdQueryCallback {
  public:
@@ -4381,6 +4430,30 @@ void Client::check_message(Slice chat_id_str, int64 message_id, bool allow_empty
              });
 }
 
+template <class OnSuccess>
+void Client::check_message_thread(int64 chat_id, int64 message_thread_id, int64 reply_to_message_id,
+                                  PromisedQueryPtr query, OnSuccess on_success) {
+  if (message_thread_id <= 0) {
+    return on_success(chat_id, 0, reply_to_message_id, std::move(query));
+  }
+
+  if (reply_to_message_id != 0) {
+    const MessageInfo *message_info = get_message(chat_id, reply_to_message_id);
+    CHECK(message_info != nullptr);
+    if (message_info->message_thread_id != message_thread_id) {
+      return fail_query_with_error(std::move(query), 400, "MESSAGE_THREAD_INVALID",
+                                   "Replied message is not in the specified message thread");
+    }
+  }
+  if (reply_to_message_id == message_thread_id) {
+    return on_success(chat_id, message_thread_id, reply_to_message_id, std::move(query));
+  }
+
+  send_request(make_object<td_api::getMessage>(chat_id, message_thread_id),
+               td::make_unique<TdOnCheckMessageThreadCallback<OnSuccess>>(
+                   this, chat_id, message_thread_id, reply_to_message_id, std::move(query), std::move(on_success)));
+}
+
 template <class OnSuccess>
 void Client::resolve_sticker_set(const td::string &sticker_set_name, PromisedQueryPtr query, OnSuccess on_success) {
   if (sticker_set_name.empty()) {
@@ -7542,16 +7615,23 @@ td::Status Client::process_send_media_group_query(PromisedQueryPtr &query) {
                            input_message_contents = std::move(input_message_contents),
                            reply_markup = std::move(reply_markup)](int64 chat_id, int64 reply_to_message_id,
                                                                    PromisedQueryPtr query) mutable {
-          auto it = yet_unsent_message_count_.find(chat_id);
-          if (it != yet_unsent_message_count_.end() && it->second > MAX_CONCURRENTLY_SENT_CHAT_MESSAGES) {
-            return query->set_retry_after_error(60);
-          }
+          auto on_message_thread_checked =
+              [this, disable_notification, protect_content, input_message_contents = std::move(input_message_contents),
+               reply_markup = std::move(reply_markup)](int64 chat_id, int64 message_thread_id,
+                                                       int64 reply_to_message_id, PromisedQueryPtr query) mutable {
+                auto it = yet_unsent_message_count_.find(chat_id);
+                if (it != yet_unsent_message_count_.end() && it->second > MAX_CONCURRENTLY_SENT_CHAT_MESSAGES) {
+                  return query->set_retry_after_error(60);
+                }
 
-          send_request(
-              make_object<td_api::sendMessageAlbum>(chat_id, message_thread_id, reply_to_message_id,
-                                                    get_message_send_options(disable_notification, protect_content),
-                                                    std::move(input_message_contents), false),
-              td::make_unique<TdOnSendMessageAlbumCallback>(this, std::move(query)));
+                send_request(make_object<td_api::sendMessageAlbum>(
+                                 chat_id, message_thread_id, reply_to_message_id,
+                                 get_message_send_options(disable_notification, protect_content),
+                                 std::move(input_message_contents), false),
+                             td::make_unique<TdOnSendMessageAlbumCallback>(this, std::move(query)));
+              };
+          check_message_thread(chat_id, message_thread_id, reply_to_message_id, std::move(query),
+                               std::move(on_message_thread_checked));
         };
         check_message(chat_id, reply_to_message_id, reply_to_message_id <= 0 || allow_sending_without_reply,
                       AccessRights::Write, "replied message", std::move(query), std::move(on_success));
@@ -9112,15 +9192,23 @@ void Client::do_send_message(object_ptr<td_api::InputMessageContent> input_messa
                            input_message_content = std::move(input_message_content),
                            reply_markup = std::move(reply_markup)](int64 chat_id, int64 reply_to_message_id,
                                                                    PromisedQueryPtr query) mutable {
-          auto it = yet_unsent_message_count_.find(chat_id);
-          if (it != yet_unsent_message_count_.end() && it->second > MAX_CONCURRENTLY_SENT_CHAT_MESSAGES) {
-            return query->set_retry_after_error(60);
-          }
+          auto on_message_thread_checked =
+              [this, disable_notification, protect_content, input_message_content = std::move(input_message_content),
+               reply_markup = std::move(reply_markup)](int64 chat_id, int64 message_thread_id,
+                                                       int64 reply_to_message_id, PromisedQueryPtr query) mutable {
+                auto it = yet_unsent_message_count_.find(chat_id);
+                if (it != yet_unsent_message_count_.end() && it->second > MAX_CONCURRENTLY_SENT_CHAT_MESSAGES) {
+                  return query->set_retry_after_error(60);
+                }
 
-          send_request(make_object<td_api::sendMessage>(chat_id, message_thread_id, reply_to_message_id,
-                                                        get_message_send_options(disable_notification, protect_content),
-                                                        std::move(reply_markup), std::move(input_message_content)),
-                       td::make_unique<TdOnSendMessageCallback>(this, std::move(query)));
+                send_request(
+                    make_object<td_api::sendMessage>(chat_id, message_thread_id, reply_to_message_id,
+                                                     get_message_send_options(disable_notification, protect_content),
+                                                     std::move(reply_markup), std::move(input_message_content)),
+                    td::make_unique<TdOnSendMessageCallback>(this, std::move(query)));
+              };
+          check_message_thread(chat_id, message_thread_id, reply_to_message_id, std::move(query),
+                               std::move(on_message_thread_checked));
         };
         check_message(chat_id, reply_to_message_id, reply_to_message_id <= 0 || allow_sending_without_reply,
                       AccessRights::Write, "replied message", std::move(query), std::move(on_success));
diff --git a/telegram-bot-api/Client.h b/telegram-bot-api/Client.h
index 555eb8f..bf5f57c 100644
--- a/telegram-bot-api/Client.h
+++ b/telegram-bot-api/Client.h
@@ -250,6 +250,8 @@ class Client final : public WebhookActor::Callback {
   template <class OnSuccess>
   class TdOnCheckMessageCallback;
   template <class OnSuccess>
+  class TdOnCheckMessageThreadCallback;
+  template <class OnSuccess>
   class TdOnCheckRemoteFileIdCallback;
   template <class OnSuccess>
   class TdOnGetChatMemberCallback;
@@ -288,6 +290,10 @@ class Client final : public WebhookActor::Callback {
   void check_message(Slice chat_id_str, int64 message_id, bool allow_empty, AccessRights access_rights,
                      Slice message_type, PromisedQueryPtr query, OnSuccess on_success);
 
+  template <class OnSuccess>
+  void check_message_thread(int64 chat_id, int64 message_thread_id, int64 reply_to_message_id, PromisedQueryPtr query,
+                            OnSuccess on_success);
+
   template <class OnSuccess>
   void resolve_sticker_set(const td::string &sticker_set_name, PromisedQueryPtr query, OnSuccess on_success);