diff --git a/Telegram/Resources/langs/rewrites/en.json b/Telegram/Resources/langs/rewrites/en.json
index 665304725..6028ca9da 100644
--- a/Telegram/Resources/langs/rewrites/en.json
+++ b/Telegram/Resources/langs/rewrites/en.json
@@ -55,6 +55,7 @@
 	"ktg_net_speed_boost_medium": "Medium",
 	"ktg_net_speed_boost_big": "Big",
 	"ktg_settings_system": "System",
+	"ktg_settings_qt_scale": "Qt scaling engine",
 	"ktg_settings_other": "Other",
 	"ktg_profile_copy_id": "Copy ID",
 	"ktg_profile_bot_id": "Bot ID",
diff --git a/Telegram/SourceFiles/core/application.cpp b/Telegram/SourceFiles/core/application.cpp
index 74bccf235..199d371fa 100644
--- a/Telegram/SourceFiles/core/application.cpp
+++ b/Telegram/SourceFiles/core/application.cpp
@@ -8,6 +8,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "core/application.h"
 
 #include "kotato/kotato_lang.h"
+#include "kotato/kotato_settings.h"
 #include "data/data_abstract_structure.h"
 #include "data/data_photo.h"
 #include "data/data_document.h"
@@ -222,9 +223,16 @@ void Application::run() {
 	_notifications = std::make_unique<Window::Notifications::System>();
 
 	startLocalStorage();
-	ValidateScale();
 	Kotato::Lang::Load(Lang::GetInstance().baseId(), Lang::GetInstance().id());
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+	if (!::Kotato::JsonSettings::GetBool("qt_scale")) {
+#endif
+		ValidateScale();
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+	}
+#endif
+
 	refreshGlobalProxy(); // Depends on app settings being read.
 
 	if (Local::oldSettingsVersion() < AppVersion) {
diff --git a/Telegram/SourceFiles/core/launcher.cpp b/Telegram/SourceFiles/core/launcher.cpp
index 2f2d8d5e7..fbbbbca12 100644
--- a/Telegram/SourceFiles/core/launcher.cpp
+++ b/Telegram/SourceFiles/core/launcher.cpp
@@ -336,6 +336,13 @@ int Launcher::exec() {
 	base::options::init(cWorkingDir() + "tdata/experimental_options.json");
 	Kotato::JsonSettings::Load();
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+	if (::Kotato::JsonSettings::GetBool("qt_scale")) {
+		QApplication::setAttribute(Qt::AA_DisableHighDpiScaling, false);
+		QApplication::setAttribute(Qt::AA_EnableHighDpiScaling, true);
+	}
+#endif
+
 	if (Logs::DebugEnabled()) {
 		const auto openalLogPath = QDir::toNativeSeparators(
 			cWorkingDir() + qsl("DebugLogs/last_openal_log.txt"));
diff --git a/Telegram/SourceFiles/core/sandbox.cpp b/Telegram/SourceFiles/core/sandbox.cpp
index 1641a58fc..bff7ba13e 100644
--- a/Telegram/SourceFiles/core/sandbox.cpp
+++ b/Telegram/SourceFiles/core/sandbox.cpp
@@ -7,6 +7,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #include "core/sandbox.h"
 
+#include "kotato/kotato_settings.h"
 #include "base/platform/base_platform_info.h"
 #include "platform/platform_specific.h"
 #include "mainwidget.h"
@@ -240,7 +241,11 @@ void Sandbox::setupScreenScale() {
 	}
 
 	const auto ratio = devicePixelRatio();
-	if (ratio > 1.) {
+	if (ratio > 1.
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+		|| ::Kotato::JsonSettings::GetBool("qt_scale")
+#endif
+		) {
 		if (!Platform::IsMac() || (ratio != 2.)) {
 			LOG(("Found non-trivial Device Pixel Ratio: %1").arg(ratio));
 			LOG(("Environmental variables: QT_DEVICE_PIXEL_RATIO='%1'").arg(qEnvironmentVariable("QT_DEVICE_PIXEL_RATIO")));
@@ -249,7 +254,11 @@ void Sandbox::setupScreenScale() {
 			LOG(("Environmental variables: QT_SCREEN_SCALE_FACTORS='%1'").arg(qEnvironmentVariable("QT_SCREEN_SCALE_FACTORS")));
 		}
 		style::SetDevicePixelRatio(int(ratio));
-		if (Platform::IsMac() && ratio == 2.) {
+		if (Platform::IsMac() && ratio == 2.
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+			&& !::Kotato::JsonSettings::GetBool("qt_scale")
+#endif
+			) {
 			cSetScreenScale(110); // 110% for Retina screens by default.
 		} else {
 			cSetScreenScale(style::kScaleDefault);
@@ -366,7 +375,12 @@ void Sandbox::singleInstanceChecked() {
 		LOG(("App Info: Detected another instance"));
 	}
 
-	Ui::DisableCustomScaling();
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+	if (!::Kotato::JsonSettings::GetBool("qt_scale")) {
+		Ui::DisableCustomScaling();
+	}
+#endif
+
 	refreshGlobalProxy();
 	if (!Logs::started() || !Logs::instanceChecked()) {
 		new NotStartedWindow();
diff --git a/Telegram/SourceFiles/kotato/kotato_settings.cpp b/Telegram/SourceFiles/kotato/kotato_settings.cpp
index 5ebf9426e..ca7597585 100644
--- a/Telegram/SourceFiles/kotato/kotato_settings.cpp
+++ b/Telegram/SourceFiles/kotato/kotato_settings.cpp
@@ -370,6 +370,12 @@ const std::map<QString, Definition, std::greater<QString>> DefinitionMap {
 	{ "always_show_top_userpic", {
 		.type = SettingType::BoolSetting,
 		.defaultValue = false, }},
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+	{ "qt_scale", {
+		.storage = SettingStorage::None,
+		.type = SettingType::BoolSetting,
+		.defaultValue = false, }},
+#endif
 };
 
 using OldOptionKey = QString;
diff --git a/Telegram/SourceFiles/kotato/kotato_settings_menu.cpp b/Telegram/SourceFiles/kotato/kotato_settings_menu.cpp
index 0111c3893..6abaabf28 100644
--- a/Telegram/SourceFiles/kotato/kotato_settings_menu.cpp
+++ b/Telegram/SourceFiles/kotato/kotato_settings_menu.cpp
@@ -395,6 +395,28 @@ void SetupKotatoSystem(
 	AddSkip(container);
 	AddSubsectionTitle(container, rktr("ktg_settings_system"));
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+	AddButton(
+		container,
+		rktr("ktg_settings_qt_scale"),
+		st::settingsButton
+	)->toggleOn(
+		rpl::single(::Kotato::JsonSettings::GetBoolWithPending("qt_scale"))
+	)->toggledValue(
+	) | rpl::filter([](bool enabled) {
+		return (enabled != ::Kotato::JsonSettings::GetBoolWithPending("qt_scale"));
+	}) | rpl::start_with_next([=](bool enabled) {
+		::Kotato::JsonSettings::SetAfterRestart("qt_scale", enabled);
+		::Kotato::JsonSettings::Write();
+
+		Ui::show(Box<Ui::ConfirmBox>(
+			tr::lng_settings_need_restart(tr::now),
+			tr::lng_settings_restart_now(tr::now),
+			tr::lng_settings_restart_later(tr::now),
+			[] { Core::Restart(); }));
+	}, container->lifetime());
+#endif // Qt < 6.0.0
+
 
 	AddSkip(container);
 }
diff --git a/Telegram/SourceFiles/settings/settings_main.cpp b/Telegram/SourceFiles/settings/settings_main.cpp
index 4018f1f4f..f9b6b4890 100644
--- a/Telegram/SourceFiles/settings/settings_main.cpp
+++ b/Telegram/SourceFiles/settings/settings_main.cpp
@@ -8,6 +8,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "settings/settings_main.h"
 
 #include "kotato/kotato_lang.h"
+#include "kotato/kotato_settings.h"
 #include "settings/settings_common.h"
 #include "settings/settings_codes.h"
 #include "settings/settings_chat.h"
@@ -173,7 +174,11 @@ void SetupSections(
 }
 
 bool HasInterfaceScale() {
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+	return !::Kotato::JsonSettings::GetBool("qt_scale");
+#else
 	return true;
+#endif
 }
 
 void SetupInterfaceScale(