diff --git a/benchmark/bench_misc.cpp b/benchmark/bench_misc.cpp
index f0a4bea06..34eda6633 100644
--- a/benchmark/bench_misc.cpp
+++ b/benchmark/bench_misc.cpp
@@ -17,6 +17,7 @@
 #include "td/utils/port/thread.h"
 #include "td/utils/Slice.h"
 #include "td/utils/SliceBuilder.h"
+#include "td/utils/Status.h"
 #include "td/utils/ThreadSafeCounter.h"
 
 #include "td/telegram/telegram_api.h"
@@ -422,7 +423,7 @@ std::atomic<td::int64> AtomicCounterBench<StrictOrder>::counter_;
 
 #endif
 
-class MessageIdDuplicateCheckerOld {
+class IdDuplicateCheckerOld {
  public:
   static td::string get_description() {
     return "Old";
@@ -453,7 +454,7 @@ class MessageIdDuplicateCheckerOld {
 };
 
 template <size_t MAX_SAVED_MESSAGE_IDS>
-class MessageIdDuplicateCheckerNew {
+class IdDuplicateCheckerNew {
  public:
   static td::string get_description() {
     return PSTRING() << "New" << MAX_SAVED_MESSAGE_IDS;
@@ -480,7 +481,7 @@ class MessageIdDuplicateCheckerNew {
   std::set<td::int64> saved_message_ids_;
 };
 
-class MessageIdDuplicateCheckerNewOther {
+class IdDuplicateCheckerNewOther {
  public:
   static td::string get_description() {
     return "NewOther";
@@ -507,7 +508,7 @@ class MessageIdDuplicateCheckerNewOther {
   std::set<td::int64> saved_message_ids_;
 };
 
-class MessageIdDuplicateCheckerNewSimple {
+class IdDuplicateCheckerNewSimple {
  public:
   static td::string get_description() {
     return "NewSimple";
@@ -534,7 +535,7 @@ class MessageIdDuplicateCheckerNewSimple {
 };
 
 template <size_t max_size>
-class MessageIdDuplicateCheckerArray {
+class IdDuplicateCheckerArray {
  public:
   static td::string get_description() {
     return PSTRING() << "Array" << max_size;
@@ -650,38 +651,38 @@ class DuplicateCheckerBenchEvenOdd final : public td::Benchmark {
 int main() {
   SET_VERBOSITY_LEVEL(VERBOSITY_NAME(DEBUG));
 
-  td::bench(DuplicateCheckerBenchEvenOdd<MessageIdDuplicateCheckerNew<1000>>());
-  td::bench(DuplicateCheckerBenchEvenOdd<MessageIdDuplicateCheckerNew<300>>());
-  td::bench(DuplicateCheckerBenchEvenOdd<MessageIdDuplicateCheckerArray<1000>>());
-  td::bench(DuplicateCheckerBenchEvenOdd<MessageIdDuplicateCheckerArray<300>>());
+  td::bench(DuplicateCheckerBenchEvenOdd<IdDuplicateCheckerNew<1000>>());
+  td::bench(DuplicateCheckerBenchEvenOdd<IdDuplicateCheckerNew<300>>());
+  td::bench(DuplicateCheckerBenchEvenOdd<IdDuplicateCheckerArray<1000>>());
+  td::bench(DuplicateCheckerBenchEvenOdd<IdDuplicateCheckerArray<300>>());
 
-  td::bench(DuplicateCheckerBenchReverse<MessageIdDuplicateCheckerNew<1000>>());
-  td::bench(DuplicateCheckerBenchReverse<MessageIdDuplicateCheckerNew<300>>());
-  td::bench(DuplicateCheckerBenchReverse<MessageIdDuplicateCheckerArray<1000>>());
-  td::bench(DuplicateCheckerBenchReverse<MessageIdDuplicateCheckerArray<300>>());
+  td::bench(DuplicateCheckerBenchReverse<IdDuplicateCheckerNew<1000>>());
+  td::bench(DuplicateCheckerBenchReverse<IdDuplicateCheckerNew<300>>());
+  td::bench(DuplicateCheckerBenchReverse<IdDuplicateCheckerArray<1000>>());
+  td::bench(DuplicateCheckerBenchReverse<IdDuplicateCheckerArray<300>>());
 
-  td::bench(DuplicateCheckerBenchRepeatOnly<MessageIdDuplicateCheckerNew<1000>>());
-  td::bench(DuplicateCheckerBenchRepeatOnly<MessageIdDuplicateCheckerNew<300>>());
-  td::bench(DuplicateCheckerBenchRepeatOnly<MessageIdDuplicateCheckerArray<1000>>());
-  td::bench(DuplicateCheckerBenchRepeatOnly<MessageIdDuplicateCheckerArray<300>>());
+  td::bench(DuplicateCheckerBenchRepeatOnly<IdDuplicateCheckerNew<1000>>());
+  td::bench(DuplicateCheckerBenchRepeatOnly<IdDuplicateCheckerNew<300>>());
+  td::bench(DuplicateCheckerBenchRepeatOnly<IdDuplicateCheckerArray<1000>>());
+  td::bench(DuplicateCheckerBenchRepeatOnly<IdDuplicateCheckerArray<300>>());
 
-  td::bench(DuplicateCheckerBenchRepeat<MessageIdDuplicateCheckerOld>());
-  td::bench(DuplicateCheckerBenchRepeat<MessageIdDuplicateCheckerNew<1000>>());
-  td::bench(DuplicateCheckerBenchRepeat<MessageIdDuplicateCheckerNewOther>());
-  td::bench(DuplicateCheckerBenchRepeat<MessageIdDuplicateCheckerNewSimple>());
-  td::bench(DuplicateCheckerBenchRepeat<MessageIdDuplicateCheckerNew<300>>());
-  td::bench(DuplicateCheckerBenchRepeat<MessageIdDuplicateCheckerArray<1000>>());
-  td::bench(DuplicateCheckerBenchRepeat<MessageIdDuplicateCheckerArray<300>>());
+  td::bench(DuplicateCheckerBenchRepeat<IdDuplicateCheckerOld>());
+  td::bench(DuplicateCheckerBenchRepeat<IdDuplicateCheckerNew<1000>>());
+  td::bench(DuplicateCheckerBenchRepeat<IdDuplicateCheckerNewOther>());
+  td::bench(DuplicateCheckerBenchRepeat<IdDuplicateCheckerNewSimple>());
+  td::bench(DuplicateCheckerBenchRepeat<IdDuplicateCheckerNew<300>>());
+  td::bench(DuplicateCheckerBenchRepeat<IdDuplicateCheckerArray<1000>>());
+  td::bench(DuplicateCheckerBenchRepeat<IdDuplicateCheckerArray<300>>());
 
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerOld>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerNew<1000>>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerNewOther>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerNewSimple>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerNew<300>>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerNew<100>>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerNew<10>>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerArray<1000>>());
-  td::bench(DuplicateCheckerBench<MessageIdDuplicateCheckerArray<300>>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerOld>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerNew<1000>>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerNewOther>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerNewSimple>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerNew<300>>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerNew<100>>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerNew<10>>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerArray<1000>>());
+  td::bench(DuplicateCheckerBench<IdDuplicateCheckerArray<300>>());
 
 #if !TD_THREAD_UNSUPPORTED
   for (int i = 1; i <= 16; i *= 2) {
diff --git a/example/cpp/td_example.cpp b/example/cpp/td_example.cpp
index 88d1c0fcc..95ed53eb5 100644
--- a/example/cpp/td_example.cpp
+++ b/example/cpp/td_example.cpp
@@ -11,7 +11,6 @@
 #include <cstdint>
 #include <functional>
 #include <iostream>
-#include <limits>
 #include <map>
 #include <memory>
 #include <sstream>
diff --git a/td/generate/scheme/td_api.tl b/td/generate/scheme/td_api.tl
index 590c4e847..e6447ec34 100644
--- a/td/generate/scheme/td_api.tl
+++ b/td/generate/scheme/td_api.tl
@@ -1776,7 +1776,7 @@ messagePinMessage message_id:int53 = MessageContent;
 //@description A screenshot of a message in the chat has been taken
 messageScreenshotTaken = MessageContent;
 
-//@description The  in the chat has been changed @theme_name New message TTL setting
+//@description A theme in the chat has been changed @theme_name If non-empty, name of the new theme set for the chat. Otherwise theme was deleted in the chat
 messageChatSetTheme theme_name:string = MessageContent;
 
 //@description The TTL (Time To Live) setting for messages in the chat has been changed @ttl New message TTL setting
diff --git a/td/mtproto/SessionConnection.cpp b/td/mtproto/SessionConnection.cpp
index 6ac30a068..6958d5631 100644
--- a/td/mtproto/SessionConnection.cpp
+++ b/td/mtproto/SessionConnection.cpp
@@ -31,7 +31,6 @@
 
 #include <algorithm>
 #include <iterator>
-#include <type_traits>
 
 namespace td {
 
diff --git a/td/telegram/CountryInfoManager.cpp b/td/telegram/CountryInfoManager.cpp
index ac561434a..e1620af80 100644
--- a/td/telegram/CountryInfoManager.cpp
+++ b/td/telegram/CountryInfoManager.cpp
@@ -18,8 +18,6 @@
 #include "td/utils/logging.h"
 #include "td/utils/misc.h"
 #include "td/utils/Random.h"
-#include "td/utils/Slice.h"
-#include "td/utils/Status.h"
 #include "td/utils/Time.h"
 #include "td/utils/tl_parsers.h"
 
diff --git a/td/telegram/CountryInfoManager.h b/td/telegram/CountryInfoManager.h
index 98e747c1c..3b4f83a1d 100644
--- a/td/telegram/CountryInfoManager.h
+++ b/td/telegram/CountryInfoManager.h
@@ -13,6 +13,7 @@
 #include "td/actor/PromiseFuture.h"
 
 #include "td/utils/common.h"
+#include "td/utils/Slice.h"
 #include "td/utils/Status.h"
 
 #include <mutex>
diff --git a/td/telegram/DocumentsManager.cpp b/td/telegram/DocumentsManager.cpp
index d2809e191..a4e995d6b 100644
--- a/td/telegram/DocumentsManager.cpp
+++ b/td/telegram/DocumentsManager.cpp
@@ -27,7 +27,6 @@
 #include "td/telegram/VoiceNotesManager.h"
 
 #include "td/utils/common.h"
-#include "td/utils/format.h"
 #include "td/utils/HttpUrl.h"
 #include "td/utils/logging.h"
 #include "td/utils/MimeType.h"
diff --git a/td/telegram/MessageContent.cpp b/td/telegram/MessageContent.cpp
index 580e4329c..492e8efe2 100644
--- a/td/telegram/MessageContent.cpp
+++ b/td/telegram/MessageContent.cpp
@@ -84,6 +84,7 @@
 #include "td/utils/tl_helpers.h"
 #include "td/utils/utf8.h"
 
+#include <limits>
 #include <utility>
 
 namespace td {
diff --git a/td/telegram/MessageEntity.cpp b/td/telegram/MessageEntity.cpp
index 42f241c66..c4e555483 100644
--- a/td/telegram/MessageEntity.cpp
+++ b/td/telegram/MessageEntity.cpp
@@ -1873,7 +1873,7 @@ Result<vector<MessageEntity>> parse_markdown(string &text) {
         case '[': {
           string url;
           if (text[i + 1] != '(') {
-            // use text as a url
+            // use text as a URL
             url.assign(text, begin_pos + 1, i - begin_pos - 1);
           } else {
             i += 2;
@@ -2070,7 +2070,7 @@ static Result<vector<MessageEntity>> do_parse_markdown_v2(CSlice text, string &r
         case MessageEntity::Type::TextUrl: {
           string url;
           if (text[i + 1] != '(') {
-            // use text as a url
+            // use text as a URL
             url = result.substr(nested_entities.back().entity_begin_pos);
           } else {
             i += 2;
diff --git a/td/telegram/MessagesManager.h b/td/telegram/MessagesManager.h
index 15a519592..0168f4930 100644
--- a/td/telegram/MessagesManager.h
+++ b/td/telegram/MessagesManager.h
@@ -31,9 +31,9 @@
 #include "td/telegram/MessageId.h"
 #include "td/telegram/MessageLinkInfo.h"
 #include "td/telegram/MessageReplyInfo.h"
-#include "td/telegram/MessageThreadInfo.h"
 #include "td/telegram/MessagesDb.h"
 #include "td/telegram/MessageSearchFilter.h"
+#include "td/telegram/MessageThreadInfo.h"
 #include "td/telegram/MessageTtlSetting.h"
 #include "td/telegram/net/NetQuery.h"
 #include "td/telegram/Notification.h"
diff --git a/td/telegram/SponsoredMessages.cpp b/td/telegram/SponsoredMessages.cpp
index 858524435..ddff5f652 100644
--- a/td/telegram/SponsoredMessages.cpp
+++ b/td/telegram/SponsoredMessages.cpp
@@ -6,6 +6,7 @@
 //
 #include "td/telegram/SponsoredMessages.h"
 
+#include "td/telegram/ChannelId.h"
 #include "td/telegram/ContactsManager.h"
 #include "td/telegram/Global.h"
 #include "td/telegram/MessageContent.h"
@@ -13,8 +14,11 @@
 #include "td/telegram/MessagesManager.h"
 #include "td/telegram/net/NetQueryCreator.h"
 #include "td/telegram/Td.h"
+#include "td/telegram/telegram_api.h"
 
-//#include "td/utils/buffer.h"
+#include "td/utils/buffer.h"
+#include "td/utils/logging.h"
+#include "td/utils/Status.h"
 
 namespace td {
 
diff --git a/td/telegram/ThemeManager.cpp b/td/telegram/ThemeManager.cpp
index 61fa1b578..deb6dc941 100644
--- a/td/telegram/ThemeManager.cpp
+++ b/td/telegram/ThemeManager.cpp
@@ -13,6 +13,7 @@
 
 #include "td/utils/algorithm.h"
 #include "td/utils/buffer.h"
+#include "td/utils/logging.h"
 
 namespace td {
 
@@ -159,7 +160,7 @@ ThemeManager::BaseTheme ThemeManager::get_base_theme(
 ThemeManager::ThemeSettings ThemeManager::get_chat_theme_settings(
     telegram_api::object_ptr<telegram_api::themeSettings> settings) {
   ThemeSettings result;
-  if (settings != nullptr && 1 <= settings->message_colors_.size() && settings->message_colors_.size() <= 4) {
+  if (settings != nullptr && !settings->message_colors_.empty() && settings->message_colors_.size() <= 4) {
     auto background =
         td_->background_manager_->on_get_background(BackgroundId(), string(), std::move(settings->wallpaper_), false);
 
diff --git a/td/telegram/ThemeManager.h b/td/telegram/ThemeManager.h
index b7cd0e05e..3e2f13a39 100644
--- a/td/telegram/ThemeManager.h
+++ b/td/telegram/ThemeManager.h
@@ -8,7 +8,7 @@
 
 #include "td/telegram/BackgroundId.h"
 #include "td/telegram/BackgroundType.h"
-#include "td/telegram/td.h"
+#include "td/telegram/td_api.h"
 #include "td/telegram/telegram_api.h"
 
 #include "td/actor/actor.h"
diff --git a/td/telegram/WebPagesManager.cpp b/td/telegram/WebPagesManager.cpp
index 65fccb1c3..8a694b9aa 100644
--- a/td/telegram/WebPagesManager.cpp
+++ b/td/telegram/WebPagesManager.cpp
@@ -51,6 +51,8 @@
 #include "td/utils/tl_helpers.h"
 #include "td/utils/utf8.h"
 
+#include <limits>
+
 namespace td {
 
 class GetWebPagePreviewQuery final : public Td::ResultHandler {
diff --git a/test/country_info.cpp b/test/country_info.cpp
index 3cbc08b7e..ca9f2376a 100644
--- a/test/country_info.cpp
+++ b/test/country_info.cpp
@@ -13,7 +13,6 @@ static void check_phone_number_info(const td::string &phone_number_prefix, const
                                     const td::string &calling_code, const td::string &formatted_phone_number) {
   auto result = td::CountryInfoManager::get_phone_number_info_sync(td::string(), phone_number_prefix);
   CHECK(result != nullptr);
-  // LOG(ERROR) << phone_number_prefix << ' ' << to_string(result);
   if (result->country_ == nullptr) {
     CHECK(country_code.empty());
   } else {