diff --git a/Telegram/SourceFiles/base/observer.h b/Telegram/SourceFiles/base/observer.h
index 57a6f05bd..2989ab870 100644
--- a/Telegram/SourceFiles/base/observer.h
+++ b/Telegram/SourceFiles/base/observer.h
@@ -357,9 +357,9 @@ class Observable : public internal::BaseObservable<EventType, Handler, base::typ
 public:
 	Observable() = default;
 	Observable(const Observable &other) = delete;
-	Observable(Observable &&other) = default;
+	Observable(Observable &&other) = delete;
 	Observable &operator=(const Observable &other) = delete;
-	Observable &operator=(Observable &&other) = default;
+	Observable &operator=(Observable &&other) = delete;
 
 };
 
diff --git a/Telegram/SourceFiles/boxes/language_box.cpp b/Telegram/SourceFiles/boxes/language_box.cpp
index 2d5ad1272..7009b9829 100644
--- a/Telegram/SourceFiles/boxes/language_box.cpp
+++ b/Telegram/SourceFiles/boxes/language_box.cpp
@@ -28,81 +28,119 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "mainwidget.h"
 #include "mainwindow.h"
 #include "lang/lang_instance.h"
+#include "lang/lang_cloud_manager.h"
 #include "styles/style_boxes.h"
 
+class LanguageBox::Inner : public TWidget {
+public:
+	Inner(QWidget *parent, gsl::not_null<Languages*> languages);
+
+	void setSelected(int index);
+	void refresh();
+
+private:
+	void languageChanged(int languageIndex);
+
+	gsl::not_null<Languages*> _languages;
+	std::shared_ptr<Ui::RadiobuttonGroup> _group;
+	std::vector<object_ptr<Ui::Radiobutton>> _buttons;
+
+};
+
+LanguageBox::Inner::Inner(QWidget *parent, gsl::not_null<Languages*> languages) : TWidget(parent)
+, _languages(languages) {
+	_group = std::make_shared<Ui::RadiobuttonGroup>(0);
+	_group->setChangedCallback([this](int value) { languageChanged(value); });
+}
+
+void LanguageBox::Inner::setSelected(int index) {
+	_group->setValue(index);
+}
+
+void LanguageBox::Inner::refresh() {
+	for (auto &button : _buttons) {
+		button.destroy();
+	}
+	_buttons.clear();
+
+	auto y = st::boxOptionListPadding.top();
+	_buttons.reserve(_languages->size());
+	auto index = 0;
+	for_const (auto &language, *_languages) {
+		_buttons.emplace_back(this, _group, index++, language.name, st::langsButton);
+		auto button = _buttons.back().data();
+		button->moveToLeft(st::boxPadding.left() + st::boxOptionListPadding.left(), y + st::langsButton.margin.top());
+		button->show();
+		y += button->heightNoMargins() + st::boxOptionListSkip;
+	}
+	auto newHeight = y + st::boxOptionListPadding.bottom() + st::boxPadding.bottom();
+	resize(st::langsWidth, newHeight);
+}
+
+void LanguageBox::Inner::languageChanged(int languageIndex) {
+	Expects(languageIndex >= 0 && languageIndex < _languages->size());
+
+	auto languageId = (*_languages)[languageIndex].id;
+	if (languageId != qsl("custom")) {
+		Lang::CurrentCloudManager().switchToLanguage(languageId);
+	}
+}
+
 void LanguageBox::prepare() {
+	refreshLangItems();
+	subscribe(Lang::Current().updated(), [this] {
+		refreshLangItems();
+	});
+
+	_inner = setInnerWidget(object_ptr<Inner>(this, &_languages), st::boxLayerScroll);
+
+	refresh();
+	subscribe(Lang::CurrentCloudManager().languageListChanged(), [this] {
+		refresh();
+	});
+}
+
+void LanguageBox::refreshLangItems() {
+	clearButtons();
 	addButton(lang(lng_box_ok), [this] { closeBox(); });
 
 	setTitle(lang(lng_languages));
 
-	request(MTPlangpack_GetLanguages()).done([this](const MTPVector<MTPLangPackLanguage> &result) {
-		auto currentId = Lang::Current().id();
-		auto currentFound = false;
-		std::vector<QString> languageIds = { qsl("en") };
-		std::vector<QString> languageNames = { qsl("English") };
-		for (auto &language : result.v) {
-			t_assert(language.type() == mtpc_langPackLanguage);
-			auto &data = language.c_langPackLanguage();
-			auto languageId = qs(data.vlang_code);
-			auto languageName = qs(data.vname);
-			if (languageId != qstr("en")) {
-				languageIds.push_back(languageId);
-				languageNames.push_back(languageName);
-			}
-		}
-		if (currentId == qstr("custom")) {
-			languageIds.insert(languageIds.begin(), currentId);
-			languageNames.insert(languageNames.begin(), qsl("Custom LangPack"));
-			currentFound = true;
-		}
-
-		auto languageCount = languageIds.size();
-		_langGroup = std::make_shared<Ui::RadiobuttonGroup>(cLang());
-		auto y = st::boxOptionListPadding.top();
-		_langs.reserve(languageCount);
-		for (auto i = 0; i != languageCount; ++i) {
-			if (!currentFound && languageIds[i] == currentId) {
-				currentFound = true;
-			}
-			_langs.emplace_back(this, _langGroup, i, languageNames[i], st::langsButton);
-			auto button = _langs.back().data();
-			button->moveToLeft(st::boxPadding.left() + st::boxOptionListPadding.left(), y + st::langsButton.margin.top());
-			button->show();
-			y += button->heightNoMargins() + st::boxOptionListSkip;
-		}
-		_langGroup->setChangedCallback([this](int value) { languageChanged(value); });
-
-		setDimensions(st::langsWidth, st::boxOptionListPadding.top() + languageCount * st::langsButton.height + languageCount * st::boxOptionListSkip + st::boxOptionListPadding.bottom() + st::boxPadding.bottom());
-	}).fail([this](const RPCError &error) {
-		closeBox();
-	}).send();
-
-	setDimensions(st::langsWidth, st::langsWidth);
+	update();
 }
 
-void LanguageBox::languageChanged(int languageId) {
-	//Expects(languageId == languageTest || (languageId >= 0 && languageId < base::array_size(LanguageCodes)));
+void LanguageBox::refresh() {
+	refreshLanguages();
 
-	//if (languageId == cLang()) {
-	//	return;
-	//}
-
-	//Lang::FileParser::Result result;
-	//if (languageId > 0) {
-	//	Lang::FileParser loader(qsl(":/langs/lang_") + LanguageCodes[languageId].c_str() + qsl(".strings"), { lng_sure_save_language, lng_cancel, lng_box_ok });
-	//	result = loader.found();
-	//} else if (languageId == languageTest) {
-	//	Lang::FileParser loader(cLangFile(), { lng_sure_save_language, lng_cancel, lng_box_ok });
-	//	result = loader.found();
-	//}
-	//auto text = result.value(lng_sure_save_language, Lang::GetOriginalValue(lng_sure_save_language)),
-	//	save = result.value(lng_box_ok, Lang::GetOriginalValue(lng_box_ok)),
-	//	cancel = result.value(lng_cancel, Lang::GetOriginalValue(lng_cancel));
-	//Ui::show(Box<ConfirmBox>(text, save, cancel, base::lambda_guarded(this, [this, languageId] {
-	//	cSetLang(languageId);
-	//	Local::writeSettings();
-	//	App::restart();
-	//}), base::lambda_guarded(this, [this] {
-	//	_langGroup->setValue(cLang());
-	//})), KeepOtherLayers);
+	_inner->refresh();
+	auto maxHeight = st::boxOptionListPadding.top() + _languages.size() * (st::langsButton.height + st::boxOptionListSkip) + st::boxOptionListPadding.bottom() + st::boxPadding.bottom();
+	setDimensions(st::langsWidth, qMin(maxHeight, st::boxMaxListHeight));
+}
+
+void LanguageBox::refreshLanguages() {
+	_languages = Languages();
+	auto list = Lang::CurrentCloudManager().languageList();
+	_languages.reserve(list.size() + 1);
+	auto currentId = Lang::Current().id();
+	auto currentIndex = -1;
+	_languages.push_back({ qsl("en"), qsl("English") });
+	for (auto &language : list) {
+		auto isCurrent = (language.id == currentId);
+		if (language.id != qstr("en")) {
+			if (isCurrent) {
+				currentIndex = _languages.size();
+			}
+			_languages.push_back(language);
+		} else if (isCurrent) {
+			currentIndex = 0;
+		}
+	}
+	if (currentId == qstr("custom")) {
+		_languages.insert(_languages.begin(), { currentId, qsl("Custom LangPack") });
+		currentIndex = 0;
+	} else if (currentIndex < 0) {
+		currentIndex = _languages.size();
+		_languages.push_back({ currentId, lang(lng_language_name) });
+	}
+	_inner->setSelected(currentIndex);
 }
diff --git a/Telegram/SourceFiles/boxes/language_box.h b/Telegram/SourceFiles/boxes/language_box.h
index 9c1d4579a..6407a7730 100644
--- a/Telegram/SourceFiles/boxes/language_box.h
+++ b/Telegram/SourceFiles/boxes/language_box.h
@@ -20,6 +20,7 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 */
 #pragma once
 
+#include "lang/lang_cloud_manager.h"
 #include "boxes/abstract_box.h"
 #include "mtproto/sender.h"
 
@@ -29,8 +30,6 @@ class Radiobutton;
 } // namespace Ui
 
 class LanguageBox : public BoxContent, private MTP::Sender {
-	Q_OBJECT
-
 public:
 	LanguageBox(QWidget*) {
 	}
@@ -39,9 +38,15 @@ protected:
 	void prepare() override;
 
 private:
-	void languageChanged(int languageId);
+	using Languages = Lang::CloudManager::Languages;
 
-	std::shared_ptr<Ui::RadiobuttonGroup> _langGroup;
-	std::vector<object_ptr<Ui::Radiobutton>> _langs;
+	void refresh();
+	void refreshLanguages();
+	void refreshLangItems();
+
+	Languages _languages;
+
+	class Inner;
+	QPointer<Inner> _inner;
 
 };
diff --git a/Telegram/SourceFiles/lang/lang_cloud_manager.cpp b/Telegram/SourceFiles/lang/lang_cloud_manager.cpp
new file mode 100644
index 000000000..a3163e837
--- /dev/null
+++ b/Telegram/SourceFiles/lang/lang_cloud_manager.cpp
@@ -0,0 +1,123 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop version of Telegram messaging app, see https://telegram.org
+
+Telegram Desktop is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+It is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+In addition, as a special exception, the copyright holders give permission
+to link the code of portions of this program with the OpenSSL library.
+
+Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
+Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
+*/
+#include "lang/lang_cloud_manager.h"
+
+#include "lang/lang_instance.h"
+#include "mtproto/mtp_instance.h"
+#include "storage/localstorage.h"
+#include "messenger.h"
+#include "apiwrap.h"
+#include "auth_session.h"
+
+namespace Lang {
+
+CloudManager::CloudManager(Instance &langpack, gsl::not_null<MTP::Instance*> mtproto) : MTP::Sender(mtproto)
+, _langpack(langpack) {
+	requestLangPackDifference();
+}
+
+void CloudManager::requestLangPackDifference() {
+	auto &langpack = Lang::Current();
+	if (langpack.isCustom() || _langPackRequestId) {
+		return;
+	}
+
+	auto version = langpack.version();
+	if (version > 0) {
+		_langPackRequestId = request(MTPlangpack_GetDifference(MTP_int(version))).done([this](const MTPLangPackDifference &result) {
+			_langPackRequestId = 0;
+			applyLangPackDifference(result);
+		}).fail([this](const RPCError &error) {
+			_langPackRequestId = 0;
+		}).send();
+	} else {
+		_langPackRequestId = request(MTPlangpack_GetLangPack()).done([this](const MTPLangPackDifference &result) {
+			_langPackRequestId = 0;
+			applyLangPackDifference(result);
+		}).fail([this](const RPCError &error) {
+			_langPackRequestId = 0;
+		}).send();
+	}
+}
+
+void CloudManager::applyLangPackDifference(const MTPLangPackDifference &difference) {
+	Expects(difference.type() == mtpc_langPackDifference);
+	auto &current = Lang::Current();
+	if (current.isCustom()) {
+		return;
+	}
+
+	auto &langpack = difference.c_langPackDifference();
+	switchLangPackId(qs(langpack.vlang_code));
+	if (current.version() < langpack.vfrom_version.v) {
+		requestLangPackDifference();
+	} else if (!langpack.vstrings.v.isEmpty()) {
+		current.applyDifference(langpack);
+		Local::writeLangPack();
+		auto fullLangPackUpdated = (langpack.vfrom_version.v == 0);
+		if (fullLangPackUpdated) {
+			Lang::Current().updated().notify();
+		}
+	} else {
+		LOG(("Lang Info: Up to date."));
+	}
+}
+
+void CloudManager::requestLanguageList() {
+	_languagesRequestId = request(MTPlangpack_GetLanguages()).done([this](const MTPVector<MTPLangPackLanguage> &result) {
+		auto languages = Languages();
+		for_const (auto &langData, result.v) {
+			t_assert(langData.type() == mtpc_langPackLanguage);
+			auto &language = langData.c_langPackLanguage();
+			languages.push_back({ qs(language.vlang_code), qs(language.vname) });
+		}
+		if (_languages != languages) {
+			_languages = languages;
+			_languagesChanged.notify();
+		}
+		_languagesRequestId = 0;
+	}).fail([this](const RPCError &error) {
+		_languagesRequestId = 0;
+	}).send();
+}
+
+void CloudManager::switchToLanguage(const QString &id) {
+	switchLangPackId(id);
+	requestLangPackDifference();
+}
+
+void CloudManager::switchLangPackId(const QString &id) {
+	auto &current = Lang::Current();
+	if (current.id() != id) {
+		current.switchToId(id);
+
+		auto mtproto = requestMTP();
+		mtproto->reInitConnection(mtproto->mainDcId());
+	}
+}
+
+CloudManager &CurrentCloudManager() {
+	auto result = Messenger::Instance().langCloudManager();
+	t_assert(result != nullptr);
+	return *result;
+}
+
+} // namespace Lang
diff --git a/Telegram/SourceFiles/lang/lang_cloud_manager.h b/Telegram/SourceFiles/lang/lang_cloud_manager.h
new file mode 100644
index 000000000..b1850fc83
--- /dev/null
+++ b/Telegram/SourceFiles/lang/lang_cloud_manager.h
@@ -0,0 +1,77 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop version of Telegram messaging app, see https://telegram.org
+
+Telegram Desktop is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+It is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+In addition, as a special exception, the copyright holders give permission
+to link the code of portions of this program with the OpenSSL library.
+
+Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
+Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
+*/
+#pragma once
+
+#include "mtproto/sender.h"
+
+namespace MTP {
+class Instance;
+} // namespace MTP
+
+namespace Lang {
+
+class Instance;
+
+class CloudManager : private MTP::Sender {
+public:
+	CloudManager(Instance &langpack, gsl::not_null<MTP::Instance*> mtproto);
+
+	struct Language {
+		QString id;
+		QString name;
+	};
+	using Languages = QVector<Language>;
+
+	void requestLanguageList();
+	Languages languageList() const {
+		return _languages;
+	}
+	base::Observable<void> &languageListChanged() {
+		return _languagesChanged;
+	}
+	void requestLangPackDifference();
+	void applyLangPackDifference(const MTPLangPackDifference &difference);
+
+	void switchToLanguage(const QString &id);
+
+private:
+	void applyLangPack(const MTPUpdates &updates);
+	void switchLangPackId(const QString &id);
+
+	Instance &_langpack;
+	Languages _languages;
+	base::Observable<void> _languagesChanged;
+	mtpRequestId _langPackRequestId = 0;
+	mtpRequestId _languagesRequestId = 0;
+
+};
+
+inline bool operator==(const CloudManager::Language &a, const CloudManager::Language &b) {
+	return (a.id == b.id) && (a.name == b.name);
+}
+
+inline bool operator!=(const CloudManager::Language &a, const CloudManager::Language &b) {
+	return !(a == b);
+}
+
+CloudManager &CurrentCloudManager();
+
+} // namespace Lang
diff --git a/Telegram/SourceFiles/lang/lang_instance.cpp b/Telegram/SourceFiles/lang/lang_instance.cpp
index b745d64e7..1f7f1ed65 100644
--- a/Telegram/SourceFiles/lang/lang_instance.cpp
+++ b/Telegram/SourceFiles/lang/lang_instance.cpp
@@ -22,9 +22,9 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 
 #include "messenger.h"
 #include "lang/lang_file_parser.h"
-#include "platform/platform_specific.h"
 #include "storage/serialize_common.h"
 #include "storage/localstorage.h"
+#include "platform/platform_specific.h"
 
 namespace Lang {
 namespace {
@@ -32,6 +32,16 @@ namespace {
 constexpr auto kDefaultLanguage = str_const("en");
 constexpr auto kLangValuesLimit = 20000;
 
+constexpr str_const kLegacyLanguages[] = {
+	"en",
+	"it",
+	"es",
+	"de",
+	"nl",
+	"pt_BR",
+	"ko",
+};
+
 class ValueParser {
 public:
 	ValueParser(const QByteArray &key, LangKey keyIndex, const QByteArray &value);
@@ -220,14 +230,38 @@ bool ValueParser::parse() {
 
 } // namespace
 
-void Instance::fillDefaults() {
+void Instance::switchToId(const QString &id) {
+	reset();
+	_id = id;
+}
+
+void Instance::switchToCustomFile(const QString &filePath) {
+	reset();
+	fillFromCustomFile(filePath);
+}
+
+void Instance::reset() {
 	_values.clear();
+	_nonDefaultValues.clear();
+	_legacyId = kLegacyLanguageNone;
+	_customFilePathAbsolute = QString();
+	_customFilePathRelative = QString();
+	_customFileContent = QByteArray();
+	_version = 0;
+
+	fillDefaults();
+}
+
+void Instance::fillDefaults() {
+	Expects(_values.empty());
 	_values.reserve(kLangKeysCount);
 	for (auto i = 0; i != kLangKeysCount; ++i) {
 		_values.emplace_back(GetOriginalValue(LangKey(i)));
 	}
-	_id = str_const_toString(kDefaultLanguage);
-	_legacyId = kLegacyDefaultLanguage;
+}
+
+QString Instance::DefaultLanguageId() {
+	return str_const_toString(kDefaultLanguage);
 }
 
 QString Instance::cloudLangCode() const {
@@ -235,7 +269,7 @@ QString Instance::cloudLangCode() const {
 		if (_systemLanguage.isEmpty()) {
 			_systemLanguage = Platform::SystemLanguage();
 			if (_systemLanguage.isEmpty()) {
-				_systemLanguage = str_const_toString(kDefaultLanguage);
+				_systemLanguage = Instance::DefaultLanguageId();
 			}
 		}
 		return _systemLanguage;
diff --git a/Telegram/SourceFiles/lang/lang_instance.h b/Telegram/SourceFiles/lang/lang_instance.h
index dc6ab770d..db2eff7ab 100644
--- a/Telegram/SourceFiles/lang/lang_instance.h
+++ b/Telegram/SourceFiles/lang/lang_instance.h
@@ -27,36 +27,23 @@ namespace Lang {
 constexpr auto kLegacyLanguageNone = -2;
 constexpr auto kLegacyCustomLanguage = -1;
 constexpr auto kLegacyDefaultLanguage = 0;
-constexpr str_const kLegacyLanguages[] = {
-	"en",
-	"it",
-	"es",
-	"de",
-	"nl",
-	"pt_BR",
-	"ko",
-};
 
 class Instance {
 public:
 	Instance() {
 		fillDefaults();
 	}
-	struct CreateFromIdTag {};
-	Instance(const QString &id, CreateFromIdTag) {
-		fillDefaults();
-		_id = id;
-	}
-	struct CreateFromCustomFileTag {};
-	Instance(const QString &filePath, CreateFromCustomFileTag) {
-		fillDefaults();
-		fillFromCustomFile(filePath);
-	}
+	void switchToId(const QString &id);
+	void switchToCustomFile(const QString &filePath);
+
 	Instance(const Instance &other) = delete;
 	Instance &operator=(const Instance &other) = delete;
 	Instance(Instance &&other) = default;
 	Instance &operator=(Instance &&other) = default;
 
+	static QString DefaultLanguageId();
+	QString cloudLangCode() const;
+
 	QString id() const {
 		return _id;
 	}
@@ -66,13 +53,15 @@ public:
 	int version() const {
 		return _version;
 	}
-	QString cloudLangCode() const;
 
 	QByteArray serialize() const;
 	void fillFromSerialized(const QByteArray &data);
 	void fillFromLegacy(int legacyId, const QString &legacyPath);
 
 	void applyDifference(const MTPDlangPackDifference &difference);
+	base::Observable<void> &updated() {
+		return _updated;
+	}
 
 	QString getValue(LangKey key) {
 		Expects(key >= 0 && key < kLangKeysCount);
@@ -83,6 +72,7 @@ public:
 private:
 	void applyValue(const QByteArray &key, const QByteArray &value);
 	void resetValue(const QByteArray &key);
+	void reset();
 	void fillDefaults();
 	void fillFromCustomFile(const QString &filePath);
 	void loadFromContent(const QByteArray &content);
@@ -94,6 +84,8 @@ private:
 	QString _customFilePathRelative;
 	QByteArray _customFileContent;
 	int _version = 0;
+	base::Observable<void> _updated;
+
 	mutable QString _systemLanguage;
 
 	std::vector<QString> _values;
diff --git a/Telegram/SourceFiles/mainwidget.cpp b/Telegram/SourceFiles/mainwidget.cpp
index 81a52abaf..b1aad6897 100644
--- a/Telegram/SourceFiles/mainwidget.cpp
+++ b/Telegram/SourceFiles/mainwidget.cpp
@@ -38,6 +38,7 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "history/history_service_layout.h"
 #include "overviewwidget.h"
 #include "lang/lang_keys.h"
+#include "lang/lang_cloud_manager.h"
 #include "boxes/add_contact_box.h"
 #include "storage/file_upload.h"
 #include "messenger.h"
@@ -5689,11 +5690,11 @@ void MainWidget::feedUpdate(const MTPUpdate &update) {
 	////// Cloud langpacks
 	case mtpc_updateLangPack: {
 		auto &langpack = update.c_updateLangPack();
-		Messenger::Instance().mtp()->applyLangPackDifference(langpack.vdifference);
+		Messenger::Instance().langCloudManager()->applyLangPackDifference(langpack.vdifference);
 	} break;
 
 	case mtpc_updateLangPackTooLong: {
-		Messenger::Instance().mtp()->requestLangPackDifference();
+		Messenger::Instance().langCloudManager()->requestLangPackDifference();
 	} break;
 
 	}
diff --git a/Telegram/SourceFiles/messenger.cpp b/Telegram/SourceFiles/messenger.cpp
index 4a4c352a4..0117bda99 100644
--- a/Telegram/SourceFiles/messenger.cpp
+++ b/Telegram/SourceFiles/messenger.cpp
@@ -31,6 +31,7 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "calls/calls_instance.h"
 #include "lang/lang_file_parser.h"
 #include "lang/lang_translator.h"
+#include "lang/lang_cloud_manager.h"
 #include "observer_peer.h"
 #include "storage/file_upload.h"
 #include "mainwidget.h"
@@ -318,6 +319,8 @@ void Messenger::startMtp() {
 		}
 		_private->storedAuthSession.reset();
 	}
+
+	_langCloudManager = std::make_unique<Lang::CloudManager>(langpack(), mtp());
 }
 
 void Messenger::destroyMtpKeys(MTP::AuthKeysList &&keys) {
diff --git a/Telegram/SourceFiles/messenger.h b/Telegram/SourceFiles/messenger.h
index 7b2aaa601..c5a8410a5 100644
--- a/Telegram/SourceFiles/messenger.h
+++ b/Telegram/SourceFiles/messenger.h
@@ -50,6 +50,7 @@ class Instance;
 namespace Lang {
 class Instance;
 class Translator;
+class CloudManager;
 } // namespace Lang
 
 class Messenger final : public QObject, public RPCSender, private base::Subscriber {
@@ -109,6 +110,9 @@ public:
 	Lang::Instance &langpack() {
 		return *_langpack;
 	}
+	Lang::CloudManager *langCloudManager() {
+		return _langCloudManager.get();
+	}
 	void authSessionCreate(UserId userId);
 	void authSessionDestroy();
 	base::Observable<void> &authSessionChanged() {
@@ -197,6 +201,7 @@ private:
 	FileUploader *_uploader = nullptr;
 
 	std::unique_ptr<Lang::Instance> _langpack;
+	std::unique_ptr<Lang::CloudManager> _langCloudManager;
 	std::unique_ptr<Lang::Translator> _translator;
 	std::unique_ptr<MTP::DcOptions> _dcOptions;
 	std::unique_ptr<MTP::Instance> _mtproto;
diff --git a/Telegram/SourceFiles/mtproto/mtp_instance.cpp b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
index 50ec31e64..22fa43982 100644
--- a/Telegram/SourceFiles/mtproto/mtp_instance.cpp
+++ b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
@@ -33,7 +33,7 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 
 namespace MTP {
 
-class Instance::Private : public Sender {
+class Instance::Private : private Sender {
 public:
 	Private(Instance *instance, DcOptions *options, Instance::Mode mode);
 
@@ -51,8 +51,6 @@ public:
 
 	void requestConfig();
 	void requestCDNConfig();
-	void requestLangPackDifference();
-	void applyLangPackDifference(const MTPLangPackDifference &difference);
 
 	void restart();
 	void restart(ShiftedDcId shiftedDcId);
@@ -64,6 +62,7 @@ public:
 	void killSession(ShiftedDcId shiftedDcId);
 	void killSession(std::unique_ptr<internal::Session> session);
 	void stopSession(ShiftedDcId shiftedDcId);
+	void reInitConnection(DcId dcId);
 	void logout(RPCDoneHandlerPtr onDone, RPCFailHandlerPtr onFail);
 
 	internal::DcenterPtr getDcById(ShiftedDcId shiftedDcId);
@@ -129,8 +128,6 @@ private:
 
 	void checkDelayedRequests();
 
-	void switchLangPackId(const QString &id);
-
 	Instance *_instance = nullptr;
 	DcOptions *_dcOptions = nullptr;
 	Instance::Mode _mode = Instance::Mode::Normal;
@@ -183,8 +180,6 @@ private:
 
 	base::Timer _checkDelayedTimer;
 
-	mtpRequestId _langPackRequestId = 0;
-
 	// Debug flag to find out how we end up crashing.
 	bool MustNotCreateSessions = false;
 
@@ -246,7 +241,6 @@ void Instance::Private::start(Config &&config) {
 	t_assert((_mainDcId == Config::kNoneMainDc) == isKeysDestroyer());
 	if (!isKeysDestroyer()) {
 		requestConfig();
-		requestLangPackDifference();
 	}
 }
 
@@ -303,58 +297,6 @@ void Instance::Private::requestCDNConfig() {
 	}).send();
 }
 
-
-void Instance::Private::requestLangPackDifference() {
-	auto &langpack = Lang::Current();
-	if (langpack.isCustom() || _langPackRequestId) {
-		return;
-	}
-
-	auto version = langpack.version();
-	if (version > 0) {
-		_langPackRequestId = request(MTPlangpack_GetDifference(MTP_int(version))).done([this](const MTPLangPackDifference &result) {
-			_langPackRequestId = 0;
-			applyLangPackDifference(result);
-		}).fail([this](const RPCError &error) {
-			_langPackRequestId = 0;
-		}).send();
-	} else {
-		_langPackRequestId = request(MTPlangpack_GetLangPack()).done([this](const MTPLangPackDifference &result) {
-			_langPackRequestId = 0;
-			applyLangPackDifference(result);
-		}).fail([this](const RPCError &error) {
-			_langPackRequestId = 0;
-		}).send();
-	}
-}
-
-void Instance::Private::applyLangPackDifference(const MTPLangPackDifference &difference) {
-	Expects(difference.type() == mtpc_langPackDifference);
-	auto &current = Lang::Current();
-	if (current.isCustom()) {
-		return;
-	}
-
-	auto &langpack = difference.c_langPackDifference();
-	switchLangPackId(qs(langpack.vlang_code));
-	if (current.version() < langpack.vfrom_version.v) {
-		requestLangPackDifference();
-	} else if (!langpack.vstrings.v.isEmpty()) {
-		current.applyDifference(langpack);
-		Local::writeLangPack();
-	} else {
-		LOG(("Lang Info: Up to date."));
-	}
-}
-
-void Instance::Private::switchLangPackId(const QString &id) {
-	auto &current = Lang::Current();
-	if (current.id() != id) {
-		current = Lang::Instance(id, Lang::Instance::CreateFromIdTag());
-		restart(maindc());
-	}
-}
-
 void Instance::Private::restart() {
 	for (auto &session : _sessions) {
 		session.second->restart();
@@ -477,7 +419,9 @@ void Instance::Private::killSession(ShiftedDcId shiftedDcId) {
 		_sessions.emplace(_mainDcId, std::move(main));
 		_mainSession->start();
 	}
-	QMetaObject::invokeMethod(_instance, "onClearKilledSessions", Qt::QueuedConnection);
+	InvokeQueued(_instance, [this] {
+		clearKilledSessions();
+	});
 }
 
 void Instance::Private::clearKilledSessions() {
@@ -493,6 +437,11 @@ void Instance::Private::stopSession(ShiftedDcId shiftedDcId) {
 	}
 }
 
+void Instance::Private::reInitConnection(DcId dcId) {
+	killSession(dcId);
+	getSession(dcId)->notifyLayerInited(false);
+}
+
 void Instance::Private::logout(RPCDoneHandlerPtr onDone, RPCFailHandlerPtr onFail) {
 	_instance->send(MTPauth_LogOut(), onDone, onFail);
 
@@ -1333,14 +1282,6 @@ void Instance::requestCDNConfig() {
 	_private->requestCDNConfig();
 }
 
-void Instance::requestLangPackDifference() {
-	_private->requestLangPackDifference();
-}
-
-void Instance::applyLangPackDifference(const MTPLangPackDifference &difference) {
-	_private->applyLangPackDifference(difference);
-}
-
 void Instance::connectionFinished(internal::Connection *connection) {
 	_private->connectionFinished(connection);
 }
@@ -1381,6 +1322,10 @@ void Instance::stopSession(ShiftedDcId shiftedDcId) {
 	_private->stopSession(shiftedDcId);
 }
 
+void Instance::reInitConnection(DcId dcId) {
+	_private->reInitConnection(dcId);
+}
+
 void Instance::logout(RPCDoneHandlerPtr onDone, RPCFailHandlerPtr onFail) {
 	_private->logout(onDone, onFail);
 }
@@ -1489,10 +1434,6 @@ void Instance::onKeyDestroyed(qint32 shiftedDcId) {
 	_private->completedKeyDestroy(shiftedDcId);
 }
 
-void Instance::onClearKilledSessions() {
-	_private->clearKilledSessions();
-}
-
 Instance::~Instance() {
 	_private->prepareToDestroy();
 }
diff --git a/Telegram/SourceFiles/mtproto/mtp_instance.h b/Telegram/SourceFiles/mtproto/mtp_instance.h
index 26ffeb899..139942e78 100644
--- a/Telegram/SourceFiles/mtproto/mtp_instance.h
+++ b/Telegram/SourceFiles/mtproto/mtp_instance.h
@@ -89,6 +89,7 @@ public:
 	int32 state(mtpRequestId requestId); // < 0 means waiting for such count of ms
 	void killSession(ShiftedDcId shiftedDcId);
 	void stopSession(ShiftedDcId shiftedDcId);
+	void reInitConnection(DcId dcId);
 	void logout(RPCDoneHandlerPtr onDone, RPCFailHandlerPtr onFail);
 
 	internal::DcenterPtr getDcById(ShiftedDcId shiftedDcId);
@@ -122,8 +123,6 @@ public:
 
 	void requestConfig();
 	void requestCDNConfig();
-	void requestLangPackDifference();
-	void applyLangPackDifference(const MTPLangPackDifference &difference);
 
 	~Instance();
 
@@ -138,7 +137,6 @@ signals:
 
 private slots:
 	void onKeyDestroyed(qint32 shiftedDcId);
-	void onClearKilledSessions();
 
 private:
 	internal::Session *getSession(ShiftedDcId shiftedDcId);
diff --git a/Telegram/SourceFiles/mtproto/sender.h b/Telegram/SourceFiles/mtproto/sender.h
index 9eb13297a..14f9e0f45 100644
--- a/Telegram/SourceFiles/mtproto/sender.h
+++ b/Telegram/SourceFiles/mtproto/sender.h
@@ -288,13 +288,16 @@ public:
 	SentRequestWrap request(mtpRequestId requestId) noexcept WARN_UNUSED_RESULT;
 
 	void requestSendDelayed() {
-		MTP::sendAnything();
+		_instance->sendAnything();
 	}
 	void requestCancellingDiscard() {
 		for (auto &request : _requests) {
 			request.handled();
 		}
 	}
+	gsl::not_null<Instance*> requestMTP() const {
+		return _instance;
+	}
 
 private:
 	class RequestWrap {
diff --git a/Telegram/SourceFiles/settings/settings_general_widget.cpp b/Telegram/SourceFiles/settings/settings_general_widget.cpp
index f364cde1e..728e54b47 100644
--- a/Telegram/SourceFiles/settings/settings_general_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_general_widget.cpp
@@ -34,6 +34,8 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "boxes/about_box.h"
 #include "core/file_utilities.h"
 #include "lang/lang_file_parser.h"
+#include "lang/lang_cloud_manager.h"
+#include "messenger.h"
 #include "autoupdater.h"
 
 namespace Settings {
@@ -220,7 +222,7 @@ void GeneralWidget::chooseCustomLang() {
 				save = result.value(lng_box_ok, Lang::GetOriginalValue(lng_box_ok)),
 				cancel = result.value(lng_cancel, Lang::GetOriginalValue(lng_cancel));
 			Ui::show(Box<ConfirmBox>(text, save, cancel, base::lambda_guarded(this, [this, filePath] {
-				Lang::Current() = Lang::Instance(filePath, Lang::Instance::CreateFromCustomFileTag());
+				Lang::Current().switchToCustomFile(filePath);
 				Local::writeLangPack();
 				onRestart();
 			})));
@@ -233,9 +235,19 @@ void GeneralWidget::chooseCustomLang() {
 void GeneralWidget::onChangeLanguage() {
 	if ((_changeLanguage->clickModifiers() & Qt::ShiftModifier) && (_changeLanguage->clickModifiers() & Qt::AltModifier)) {
 		chooseCustomLang();
+		return;
+	}
+	auto manager = Messenger::Instance().langCloudManager();
+	if (manager->languageList().isEmpty()) {
+		_languagesLoadedSubscription = subscribe(manager->languageListChanged(), [this] {
+			unsubscribe(base::take(_languagesLoadedSubscription));
+			Ui::show(Box<LanguageBox>());
+		});
 	} else {
+		unsubscribe(base::take(_languagesLoadedSubscription));
 		Ui::show(Box<LanguageBox>());
 	}
+	manager->requestLanguageList();
 }
 
 void GeneralWidget::onRestart() {
diff --git a/Telegram/SourceFiles/settings/settings_general_widget.h b/Telegram/SourceFiles/settings/settings_general_widget.h
index 1c1d0942c..04f9c54ad 100644
--- a/Telegram/SourceFiles/settings/settings_general_widget.h
+++ b/Telegram/SourceFiles/settings/settings_general_widget.h
@@ -117,6 +117,8 @@ private:
 	object_ptr<Ui::WidgetSlideWrap<Ui::Checkbox>> _startMinimized = { nullptr };
 	object_ptr<Ui::Checkbox> _addInSendTo = { nullptr };
 
+	int _languagesLoadedSubscription = 0;
+
 };
 
 } // namespace Settings
diff --git a/Telegram/gyp/telegram_sources.txt b/Telegram/gyp/telegram_sources.txt
index dc574336a..13b24dc59 100644
--- a/Telegram/gyp/telegram_sources.txt
+++ b/Telegram/gyp/telegram_sources.txt
@@ -177,6 +177,8 @@
 <(src_loc)/intro/introsignup.h
 <(src_loc)/intro/introstart.cpp
 <(src_loc)/intro/introstart.h
+<(src_loc)/lang/lang_cloud_manager.cpp
+<(src_loc)/lang/lang_cloud_manager.h
 <(src_loc)/lang/lang_file_parser.cpp
 <(src_loc)/lang/lang_file_parser.h
 <(src_loc)/lang/lang_instance.cpp