diff --git a/Telegram/SourceFiles/main.cpp b/Telegram/SourceFiles/main.cpp
index 6cd942ec..d8ce29b9 100644
--- a/Telegram/SourceFiles/main.cpp
+++ b/Telegram/SourceFiles/main.cpp
@@ -23,9 +23,10 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "storage/localstorage.h"
 
 int main(int argc, char *argv[]) {
-#ifndef Q_OS_MAC // Retina display support is working fine, others are not.
+#if !defined(Q_OS_MAC) && QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
+	// Retina display support is working fine, others are not.
 	QCoreApplication::setAttribute(Qt::AA_DisableHighDpiScaling, true);
-#endif // Q_OS_MAC
+#endif // not defined Q_OS_MAC and QT_VERSION >= 5.6.0
 	QCoreApplication::setApplicationName(qsl("TelegramDesktop"));
 
 	settingsParseArgs(argc, argv);
@@ -39,6 +40,11 @@ int main(int argc, char *argv[]) {
 	Logs::start(); // must be started before Platform is started
 	Platform::start(); // must be started before QApplication is created
 
+	// I don't know why path is not in QT_PLUGIN_PATH by default
+	QCoreApplication::addLibraryPath("/usr/lib/qt/plugins");
+	// without this Telegram doesn't start on Ubuntu 17.04 due GTK errors
+	setenv("QT_STYLE_OVERRIDE", "qwerty", false);
+
 	int result = 0;
 	{
 		Application app(argc, argv);
diff --git a/Telegram/SourceFiles/platform/linux/linux_libs.h b/Telegram/SourceFiles/platform/linux/linux_libs.h
index a8bf969c..75593540 100644
--- a/Telegram/SourceFiles/platform/linux/linux_libs.h
+++ b/Telegram/SourceFiles/platform/linux/linux_libs.h
@@ -29,7 +29,7 @@ extern "C" {
 } // extern "C"
 
 #ifndef TDESKTOP_DISABLE_UNITY_INTEGRATION
-#include <unity/unity/unity.h>
+typedef void UnityLauncherEntry;
 #endif // !TDESKTOP_DISABLE_UNITY_INTEGRATION
 
 namespace Platform {
diff --git a/Telegram/SourceFiles/qt_functions.cpp b/Telegram/SourceFiles/qt_functions.cpp
new file mode 100644
index 00000000..4a722b8d
--- /dev/null
+++ b/Telegram/SourceFiles/qt_functions.cpp
@@ -0,0 +1,94 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file contains some parts of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/* TODO: find a dynamic library with these symbols. */
+
+/* Debian maintainer: this function is taken from qfiledialog.cpp */
+/*
+    Makes a list of filters from ;;-separated text.
+    Used by the mac and windows implementations
+*/
+QStringList qt_make_filter_list(const QString &filter)
+{
+    QString f(filter);
+
+    if (f.isEmpty())
+        return QStringList();
+
+    QString sep(QLatin1String(";;"));
+    int i = f.indexOf(sep, 0);
+    if (i == -1) {
+        if (f.indexOf(QLatin1Char('\n'), 0) != -1) {
+            sep = QLatin1Char('\n');
+            i = f.indexOf(sep, 0);
+        }
+    }
+
+    return f.split(sep);
+}
+
+/* Debian maintainer: this constructor is taken from qtextengine.cpp for TextPainter::drawLine */
+QTextItemInt::QTextItemInt(const QGlyphLayout &g, QFont *font, const QChar *chars_, int numChars, QFontEngine *fe, const QTextCharFormat &format)
+    : flags(0), justified(false), underlineStyle(QTextCharFormat::NoUnderline), charFormat(format),
+      num_chars(numChars), chars(chars_), logClusters(0), f(font),  glyphs(g), fontEngine(fe)
+{
+}
+
+/* Debian maintainer: this method is also taken from qtextengine.cpp */
+// Fix up flags and underlineStyle with given info
+void QTextItemInt::initWithScriptItem(const QScriptItem &si)
+{
+    // explicitly initialize flags so that initFontAttributes can be called
+    // multiple times on the same TextItem
+    flags = 0;
+    if (si.analysis.bidiLevel %2)
+        flags |= QTextItem::RightToLeft;
+    ascent = si.ascent;
+    descent = si.descent;
+
+    if (charFormat.hasProperty(QTextFormat::TextUnderlineStyle)) {
+        underlineStyle = charFormat.underlineStyle();
+    } else if (charFormat.boolProperty(QTextFormat::FontUnderline)
+               || f->d->underline) {
+        underlineStyle = QTextCharFormat::SingleUnderline;
+    }
+
+    // compat
+    if (underlineStyle == QTextCharFormat::SingleUnderline)
+        flags |= QTextItem::Underline;
+
+    if (f->d->overline || charFormat.fontOverline())
+        flags |= QTextItem::Overline;
+    if (f->d->strikeOut || charFormat.fontStrikeOut())
+        flags |= QTextItem::StrikeOut;
+}
diff --git a/Telegram/SourceFiles/qt_static_plugins.cpp b/Telegram/SourceFiles/qt_static_plugins.cpp
index b975c7a8..f2f876b3 100644
--- a/Telegram/SourceFiles/qt_static_plugins.cpp
+++ b/Telegram/SourceFiles/qt_static_plugins.cpp
@@ -28,13 +28,4 @@ Q_IMPORT_PLUGIN(QWebpPlugin)
 Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin)
 Q_IMPORT_PLUGIN(QGenericEnginePlugin)
 #elif defined Q_OS_LINUX // Q_OS_WIN | Q_OS_MAC
-Q_IMPORT_PLUGIN(QWebpPlugin)
-Q_IMPORT_PLUGIN(QXcbIntegrationPlugin)
-Q_IMPORT_PLUGIN(QConnmanEnginePlugin)
-Q_IMPORT_PLUGIN(QGenericEnginePlugin)
-Q_IMPORT_PLUGIN(QNetworkManagerEnginePlugin)
-Q_IMPORT_PLUGIN(QComposePlatformInputContextPlugin)
-Q_IMPORT_PLUGIN(QIbusPlatformInputContextPlugin)
-Q_IMPORT_PLUGIN(QFcitxPlatformInputContextPlugin)
-Q_IMPORT_PLUGIN(QHimePlatformInputContextPlugin)
 #endif // Q_OS_WIN | Q_OS_MAC | Q_OS_LINUX
diff --git a/Telegram/SourceFiles/ui/text/text.cpp b/Telegram/SourceFiles/ui/text/text.cpp
index 044f8716..0865a5bb 100644
--- a/Telegram/SourceFiles/ui/text/text.cpp
+++ b/Telegram/SourceFiles/ui/text/text.cpp
@@ -1692,11 +1692,11 @@ private:
 		if (item == -1)
 			return;
 
-#ifdef OS_MAC_OLD
+#if defined(OS_MAC_OLD) || QT_VERSION < QT_VERSION_CHECK(5, 6, 0)
 		auto end = _e->findItem(line.from + line.length - 1);
-#else // OS_MAC_OLD
+#else
 		auto end = _e->findItem(line.from + line.length - 1, item);
-#endif // OS_MAC_OLD
+#endif
 
 		int blockIndex = _lineStartBlock;
 		ITextBlock *currentBlock = _t->_blocks[blockIndex];
diff --git a/Telegram/SourceFiles/ui/text/text_block.cpp b/Telegram/SourceFiles/ui/text/text_block.cpp
index f89644e1..35230cfc 100644
--- a/Telegram/SourceFiles/ui/text/text_block.cpp
+++ b/Telegram/SourceFiles/ui/text/text_block.cpp
@@ -330,7 +330,7 @@ TextBlock::TextBlock(const style::font &font, const QString &str, QFixed minResi
 		SignalHandlers::setCrashAnnotationRef("CrashString", &part);
 
 		QStackTextEngine engine(part, blockFont->f);
-		QTextLayout layout(&engine);
+		QTextLayout layout(part, blockFont->f);
 		layout.beginLayout();
 		layout.createLine();
 
diff --git a/Telegram/SourceFiles/ui/twidget.cpp b/Telegram/SourceFiles/ui/twidget.cpp
index e9848ef2..dcee47ee 100644
--- a/Telegram/SourceFiles/ui/twidget.cpp
+++ b/Telegram/SourceFiles/ui/twidget.cpp
@@ -191,9 +191,9 @@ void sendSynteticMouseEvent(QWidget *widget, QEvent::Type type, Qt::MouseButton
 			, button
 			, QGuiApplication::mouseButtons() | button
 			, QGuiApplication::keyboardModifiers()
-#ifndef OS_MAC_OLD
+#if !defined(OS_MAC_OLD) && QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
 			, Qt::MouseEventSynthesizedByApplication
-#endif // OS_MAC_OLD
+#endif
 		);
 		ev.setTimestamp(getms());
 		QGuiApplication::sendEvent(windowHandle, &ev);
diff --git a/Telegram/gyp/PrecompiledHeader.cmake b/Telegram/gyp/PrecompiledHeader.cmake
index 5d6830e9..c3f08d3f 100644
--- a/Telegram/gyp/PrecompiledHeader.cmake
+++ b/Telegram/gyp/PrecompiledHeader.cmake
@@ -112,7 +112,7 @@ function(add_precompiled_header _target _input)
       set(_compiler_FLAGS "@${_pch_c_flags_file}")
       add_custom_command(
         OUTPUT "${_output_c}"
-        COMMAND "${CMAKE_C_COMPILER}" ${_compiler_FLAGS} -x c-header -o "${_output_c}" -c "${_pchfile}"
+        COMMAND "${CMAKE_C_COMPILER}" "$(C_DEFINES)" "$(C_INCLUDES)" "$(C_FLAGS)" -x c-header -o "${_output_c}" -c "${_pchfile}"
         DEPENDS "${_pchfile}" "${_pch_c_flags_file}"
         IMPLICIT_DEPENDS C "${_pch_header}"
         COMMENT "Precompiling ${_name} for ${_target} (C)")
@@ -123,7 +123,7 @@ function(add_precompiled_header _target _input)
       set(_compiler_FLAGS "@${_pch_cpp_flags_file}")
       add_custom_command(
         OUTPUT "${_output_cxx}"
-        COMMAND "${CMAKE_CXX_COMPILER}" ${_compiler_FLAGS} -x c++-header -o "${_output_cxx}" -c "${_pchfile}"
+        COMMAND "${CMAKE_CXX_COMPILER}" "$(CXX_DEFINES)" "$(CXX_INCLUDES)" "$(CXX_FLAGS)" -x c++-header -o "${_output_cxx}" -c "${_pchfile}"
         DEPENDS "${_pchfile}" "${_pch_cpp_flags_file}"
         IMPLICIT_DEPENDS CXX "${_pch_header}"
         COMMENT "Precompiling ${_name} for ${_target} (C++)")
diff --git a/Telegram/gyp/Telegram.gyp b/Telegram/gyp/Telegram.gyp
index 80160d16..8789e874 100644
--- a/Telegram/gyp/Telegram.gyp
+++ b/Telegram/gyp/Telegram.gyp
@@ -78,12 +78,10 @@
       'codegen.gyp:codegen_lang',
       'codegen.gyp:codegen_numbers',
       'codegen.gyp:codegen_style',
-      'utils.gyp:Updater',
       '../ThirdParty/libtgvoip/libtgvoip.gyp:libtgvoip',
     ],
 
     'defines': [
-      'AL_LIBTYPE_STATIC',
       'AL_ALEXT_PROTOTYPES',
       'TGVOIP_USE_CXX11_LIB',
       '<!@(python -c "for s in \'<(build_defines)\'.split(\',\'): print(s)")',
@@ -92,14 +90,7 @@
     'include_dirs': [
       '<(src_loc)',
       '<(SHARED_INTERMEDIATE_DIR)',
-      '<(libs_loc)/breakpad/src',
-      '<(libs_loc)/lzma/C',
-      '<(libs_loc)/libexif-0.6.20',
-      '<(libs_loc)/zlib-1.2.8',
-      '<(libs_loc)/ffmpeg',
-      '<(libs_loc)/openal-soft/include',
-      '<(libs_loc)/opus/include',
-      '<(minizip_loc)',
+      '/usr/include/minizip',
       '<(sp_media_key_tap_loc)',
       '<(submodules_loc)/GSL/include',
       '<(submodules_loc)/variant/include',
diff --git a/Telegram/gyp/qt.gypi b/Telegram/gyp/qt.gypi
index 81c13a18..99af0edb 100644
--- a/Telegram/gyp/qt.gypi
+++ b/Telegram/gyp/qt.gypi
@@ -27,25 +27,21 @@
               [ 'build_macold', {
                 'qt_version%': '5.3.2',
               }, {
-                'qt_version%': '5.6.2',
+                'qt_version%': '5.9.1',
               }]
             ],
           },
           'qt_libs': [
-            'qwebp',
-            'Qt5PrintSupport',
-            'Qt5PlatformSupport',
             'Qt5Network',
             'Qt5Widgets',
             'Qt5Gui',
-            'qtharfbuzzng',
           ],
           'qt_version%': '<(qt_version)',
           'conditions': [
             [ 'build_macold', {
               'linux_path_qt%': '/usr/local/macold/Qt-<(qt_version)',
             }, {
-              'linux_path_qt%': '/usr/local/tdesktop/Qt-<(qt_version)',
+              'linux_path_qt%': '/usr/lib/qt',
             }]
           ]
         },
@@ -85,32 +81,12 @@
             ],
           }],
           [ 'build_linux', {
-            'qt_lib_prefix': 'lib',
-            'qt_lib_debug_postfix': '.a',
-            'qt_lib_release_postfix': '.a',
+            'qt_lib_prefix': '',
+            'qt_lib_debug_postfix': '',
+            'qt_lib_release_postfix': '',
             'qt_libs': [
-              'qxcb',
-              'Qt5XcbQpa',
-              'qconnmanbearer',
-              'qgenericbearer',
-              'qnmbearer',
               '<@(qt_libs)',
-              'Qt5DBus',
               'Qt5Core',
-              'qtpcre',
-              'Xi',
-              'Xext',
-              'Xfixes',
-              'SM',
-              'ICE',
-              'fontconfig',
-              'expat',
-              'freetype',
-              'z',
-              'xcb-shm',
-              'xcb-xfixes',
-              'xcb-render',
-              'xcb-static',
             ],
           }],
         ],
@@ -140,11 +116,6 @@
     # '<!@(python <(DEPTH)/list_sources.py [sources] <(qt_moc_list_sources_arg))'
     # where [sources] contains all your source files
     'qt_moc_list_sources_arg': '--moc-prefix SHARED_INTERMEDIATE_DIR/<(_target_name)/moc/moc_',
-
-    'linux_path_xkbcommon%': '/usr/local',
-    'linux_lib_ssl%': '/usr/local/ssl/lib/libssl.a',
-    'linux_lib_crypto%': '/usr/local/ssl/lib/libcrypto.a',
-    'linux_lib_icu%': '/usr/lib/libicutu.a /usr/lib/libicui18n.a /usr/lib/libicuuc.a /usr/lib/libicudata.a',
   },
 
   'configurations': {
@@ -193,13 +164,13 @@
   },
 
   'include_dirs': [
-    '<(qt_loc)/include',
-    '<(qt_loc)/include/QtCore',
-    '<(qt_loc)/include/QtGui',
-    '<(qt_loc)/include/QtCore/<(qt_version)',
-    '<(qt_loc)/include/QtGui/<(qt_version)',
-    '<(qt_loc)/include/QtCore/<(qt_version)/QtCore',
-    '<(qt_loc)/include/QtGui/<(qt_version)/QtGui',
+    '/usr/include/qt',
+    '/usr/include/qt/QtCore',
+    '/usr/include/qt/QtGui',
+    '/usr/include/qt/QtCore/<(qt_version)',
+    '/usr/include/qt/QtGui/<(qt_version)',
+    '/usr/include/qt/QtCore/<(qt_version)/QtCore',
+    '/usr/include/qt/QtGui/<(qt_version)/QtGui',
   ],
   'library_dirs': [
     '<(qt_loc)/lib',
@@ -220,11 +191,8 @@
         '<(qt_loc)/plugins/platforminputcontexts',
       ],
       'libraries': [
-        '<(linux_path_xkbcommon)/lib/libxkbcommon.a',
         '<@(qt_libs_release)',
-        '<(linux_lib_ssl)',
-        '<(linux_lib_crypto)',
-        '<!@(python -c "for s in \'<(linux_lib_icu)\'.split(\' \'): print(s)")',
+        'crypto',
         'xcb',
         'X11',
         'X11-xcb',
@@ -238,7 +206,6 @@
         '<(qt_loc)/mkspecs/linux-g++',
       ],
       'ldflags': [
-        '-static-libstdc++',
         '-pthread',
         '-g',
         '-rdynamic',
@@ -260,7 +227,7 @@
       '<(SHARED_INTERMEDIATE_DIR)/<(_target_name)/moc/moc_<(RULE_INPUT_ROOT).cpp',
     ],
     'action': [
-      '<(qt_loc)/bin/moc<(exe_ext)',
+      '/usr/bin/moc',
 
       # Silence "Note: No relevant classes found. No output generated."
       '--no-notes',
diff --git a/Telegram/gyp/qt_rcc.gypi b/Telegram/gyp/qt_rcc.gypi
index eebc6967..19a346fe 100644
--- a/Telegram/gyp/qt_rcc.gypi
+++ b/Telegram/gyp/qt_rcc.gypi
@@ -28,7 +28,7 @@
       '<(SHARED_INTERMEDIATE_DIR)/<(_target_name)/qrc/qrc_<(RULE_INPUT_ROOT).cpp',
     ],
     'action': [
-      '<(qt_loc)/bin/rcc<(exe_ext)',
+      '/usr/bin/rcc',
       '-name', '<(RULE_INPUT_ROOT)',
       '-no-compress',
       '<(RULE_INPUT_PATH)',
diff --git a/Telegram/gyp/settings_linux.gypi b/Telegram/gyp/settings_linux.gypi
index fde88dcd..ca149b85 100644
--- a/Telegram/gyp/settings_linux.gypi
+++ b/Telegram/gyp/settings_linux.gypi
@@ -25,7 +25,6 @@
           '-pipe',
           '-g',
           '-Wall',
-          '-Werror',
           '-W',
           '-fPIC',
           '-Wno-unused-variable',
@@ -61,7 +60,6 @@
       ],
       'defines': [
         '_REENTRANT',
-        'QT_STATICPLUGIN',
         'QT_PLUGIN',
       ],
       'cflags_c': [
diff --git a/Telegram/gyp/telegram_linux.gypi b/Telegram/gyp/telegram_linux.gypi
index 2c464928..b505a67d 100644
--- a/Telegram/gyp/telegram_linux.gypi
+++ b/Telegram/gyp/telegram_linux.gypi
@@ -33,9 +33,10 @@
       'linux_path_va%': '/usr/local',
       'linux_path_vdpau%': '/usr/local',
       'linux_path_breakpad%': '<(libs_loc)/breakpad',
-      'linux_path_opus_include%': '<(libs_loc)/opus/include',
+      'linux_path_opus_include%': '/usr/include/opus',
     },
     'include_dirs': [
+      '/usr/include/openssl-1.0',
       '/usr/local/include',
       '<(linux_path_ffmpeg)/include',
       '<(linux_path_openal)/include',
@@ -43,6 +44,7 @@
       '<(linux_path_opus_include)',
     ],
     'library_dirs': [
+      '/usr/lib/openssl-1.0',
       '/usr/local/lib',
       '<(linux_path_ffmpeg)/lib',
       '<(linux_path_openal)/lib',
@@ -52,31 +54,20 @@
       '<(linux_path_breakpad)/lib',
     ],
     'libraries': [
-      'breakpad_client',
-      'composeplatforminputcontextplugin',
-      'ibusplatforminputcontextplugin',
-      'fcitxplatforminputcontextplugin',
-      'himeplatforminputcontextplugin',
-      'liblzma.a',
-      'libopenal.a',
-      'libavformat.a',
-      'libavcodec.a',
-      'libswresample.a',
-      'libswscale.a',
-      'libavutil.a',
-      'libopus.a',
-      'libva-x11.a',
-      'libva-drm.a',
-      'libva.a',
-      'libvdpau.a',
-      'libdrm.a',
-      'libz.a',
+      'openal',
+      'avformat',
+      'avcodec',
+      'swresample',
+      'swscale',
+      'avutil',
+      'minizip',
+      'opus',
+      'z',
 #      '<!(pkg-config 2> /dev/null --libs <@(pkgconfig_libs))',
     ],
     'cflags_cc': [
       '<!(pkg-config 2> /dev/null --cflags appindicator-0.1)',
-      '<!(pkg-config 2> /dev/null --cflags gtk+-2.0)',
-      '<!(pkg-config 2> /dev/null --cflags glib-2.0)',
+      '<!(pkg-config 2> /dev/null --cflags gtk+-3.0)',
       '<!(pkg-config 2> /dev/null --cflags dee-1.0)',
     ],
     'configurations': {
diff --git a/Telegram/gyp/telegram_sources.txt b/Telegram/gyp/telegram_sources.txt
index fbe63ec5..475210b3 100644
--- a/Telegram/gyp/telegram_sources.txt
+++ b/Telegram/gyp/telegram_sources.txt
@@ -580,14 +580,7 @@
 <(src_loc)/structs.cpp
 <(src_loc)/structs.h
 
-platforms: !win
-<(minizip_loc)/crypt.h
-<(minizip_loc)/ioapi.c
-<(minizip_loc)/ioapi.h
-<(minizip_loc)/zip.c
-<(minizip_loc)/zip.h
-<(minizip_loc)/unzip.c
-<(minizip_loc)/unzip.h
+<(src_loc)/qt_functions.cpp
 
 platforms: mac
 <(sp_media_key_tap_loc)/SPMediaKeyTap.m