diff --git a/CMakeLists.txt b/CMakeLists.txt
index e2c64f60ae..e7183f1691 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -512,14 +512,8 @@ else()
     find_package(Qt5 COMPONENTS ${QT_COMPONENTS} REQUIRED)
 endif()
 
-if(Qt5Core_VERSION VERSION_LESS "5.2.0")
-    message(FATAL_ERROR "Qt version 5.2.0 or higher is required")
-endif()
-
-# CBOR for Passkeys requires Qt 5.12
 if(Qt5Core_VERSION VERSION_LESS "5.12.0")
-    message(STATUS "Qt version 5.12.0 or higher is required for Passkeys support")
-    set(WITH_XC_BROWSER_PASSKEYS OFF)
+    message(FATAL_ERROR "Qt version 5.12.0 or higher is required")
 endif()
 
 get_filename_component(Qt5_PREFIX ${Qt5_DIR}/../../.. REALPATH)
diff --git a/share/translations/keepassxc_en.ts b/share/translations/keepassxc_en.ts
index ced96cab57..31117b206b 100644
--- a/share/translations/keepassxc_en.ts
+++ b/share/translations/keepassxc_en.ts
@@ -5701,11 +5701,6 @@ This version is not meant for production use.</source>
 Expect some bugs and minor issues, this version is meant for testing purposes.</source>
         <translation type="unfinished"></translation>
     </message>
-    <message>
-        <source>WARNING: Your Qt version may cause KeePassXC to crash with an On-Screen Keyboard.
-We recommend you use the AppImage available on our downloads page.</source>
-        <translation type="unfinished"></translation>
-    </message>
     <message>
         <source>No Tags</source>
         <translation type="unfinished"></translation>
diff --git a/src/autotype/AutoTypeSelectDialog.cpp b/src/autotype/AutoTypeSelectDialog.cpp
index ce8c61cf3c..c8fa1480e3 100644
--- a/src/autotype/AutoTypeSelectDialog.cpp
+++ b/src/autotype/AutoTypeSelectDialog.cpp
@@ -21,12 +21,8 @@
 
 #include <QCloseEvent>
 #include <QMenu>
-#include <QShortcut>
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
 #include <QScreen>
-#else
-#include <QDesktopWidget>
-#endif
+#include <QShortcut>
 
 #include "core/Config.h"
 #include "core/Database.h"
@@ -334,7 +330,6 @@ void AutoTypeSelectDialog::buildActionMenu()
     });
 #endif
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
     // Qt 5.10 introduced a new "feature" to hide shortcuts in context menus
     // Unfortunately, Qt::AA_DontShowShortcutsInContextMenus is broken, have to manually enable them
     typeUsernameAction->setShortcutVisibleInContextMenu(true);
@@ -342,7 +337,6 @@ void AutoTypeSelectDialog::buildActionMenu()
     typeTotpAction->setShortcutVisibleInContextMenu(true);
 #if defined(Q_OS_WIN) || defined(Q_OS_MAC)
     typeVirtualAction->setShortcutVisibleInContextMenu(true);
-#endif
 #endif
 
     copyUsernameAction->setProperty(MENU_FIELD_PROP_NAME, MENU_FIELD::USERNAME);
@@ -377,16 +371,12 @@ void AutoTypeSelectDialog::showEvent(QShowEvent* event)
 {
     QDialog::showEvent(event);
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
     auto screen = QApplication::screenAt(QCursor::pos());
     if (!screen) {
         // screenAt can return a nullptr, default to the primary screen
         screen = QApplication::primaryScreen();
     }
     QRect screenGeometry = screen->availableGeometry();
-#else
-    QRect screenGeometry = QApplication::desktop()->availableGeometry(QCursor::pos());
-#endif
 
     // Resize to last used size
     QSize size = config()->get(Config::GUI_AutoTypeSelectDialogSize).toSize();
diff --git a/src/autotype/PickcharsDialog.cpp b/src/autotype/PickcharsDialog.cpp
index 798f2e228b..54ef34b5f9 100644
--- a/src/autotype/PickcharsDialog.cpp
+++ b/src/autotype/PickcharsDialog.cpp
@@ -21,12 +21,8 @@
 #include "gui/Icons.h"
 
 #include <QPushButton>
-#include <QShortcut>
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
 #include <QScreen>
-#else
-#include <QDesktopWidget>
-#endif
+#include <QShortcut>
 
 PickcharsDialog::PickcharsDialog(const QString& string, QWidget* parent)
     : QDialog(parent)
@@ -157,15 +153,11 @@ void PickcharsDialog::showEvent(QShowEvent* event)
     QDialog::showEvent(event);
 
     // Center on active screen
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
     auto screen = QApplication::screenAt(QCursor::pos());
     if (!screen) {
         // screenAt can return a nullptr, default to the primary screen
         screen = QApplication::primaryScreen();
     }
     QRect screenGeometry = screen->availableGeometry();
-#else
-    QRect screenGeometry = QApplication::desktop()->availableGeometry(QCursor::pos());
-#endif
     move(screenGeometry.center().x() - (size().width() / 2), screenGeometry.center().y() - (size().height() / 2));
 }
diff --git a/src/core/Config.cpp b/src/core/Config.cpp
index c61df1f498..07a70210e9 100644
--- a/src/core/Config.cpp
+++ b/src/core/Config.cpp
@@ -219,7 +219,6 @@ static const QHash<Config::ConfigKey, ConfigDirective> configStrings = {
 
     // Messages
     {Config::Messages_NoLegacyKeyFileWarning, {QS("Messages/NoLegacyKeyFileWarning"), Roaming, false}},
-    {Config::Messages_Qt55CompatibilityWarning, {QS("Messages/Qt55CompatibilityWarning"), Local, false}},
     {Config::Messages_HidePreReleaseWarning, {QS("Messages/HidePreReleaseWarning"), Local, {}}}};
 
 // clang-format on
@@ -360,7 +359,7 @@ static const QHash<QString, Config::ConfigKey> deprecationMap = {
     {QS("generator/WordList"), Config::PasswordGenerator_WordList},
     {QS("generator/WordCase"), Config::PasswordGenerator_WordCase},
     {QS("generator/Type"), Config::PasswordGenerator_Type},
-    {QS("QtErrorMessageShown"), Config::Messages_Qt55CompatibilityWarning},
+    {QS("QtErrorMessageShown"), Config::Deleted},
     {QS("GUI/HidePasswords"), Config::Deleted},
     {QS("GUI/DarkTrayIcon"), Config::Deleted},
 
diff --git a/src/core/Config.h b/src/core/Config.h
index 53c910a7d2..ef7aa5fcaf 100644
--- a/src/core/Config.h
+++ b/src/core/Config.h
@@ -194,7 +194,6 @@ class Config : public QObject
         PasswordGenerator_Type,
 
         Messages_NoLegacyKeyFileWarning,
-        Messages_Qt55CompatibilityWarning,
         Messages_HidePreReleaseWarning,
 
         // Special internal value
diff --git a/src/core/Database.cpp b/src/core/Database.cpp
index 031955c1e0..3cd7f6033a 100644
--- a/src/core/Database.cpp
+++ b/src/core/Database.cpp
@@ -318,10 +318,8 @@ bool Database::performSave(const QString& filePath, SaveAction action, const QSt
         backupDatabase(filePath, backupFilePath);
     }
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
     QFileInfo info(filePath);
     auto createTime = info.exists() ? info.birthTime() : QDateTime::currentDateTime();
-#endif
 
     switch (action) {
     case Atomic: {
@@ -332,10 +330,8 @@ bool Database::performSave(const QString& filePath, SaveAction action, const QSt
                 return false;
             }
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
             // Retain original creation time
             saveFile.setFileTime(createTime, QFile::FileBirthTime);
-#endif
 
             if (saveFile.commit()) {
                 // successfully saved database file
@@ -368,10 +364,8 @@ bool Database::performSave(const QString& filePath, SaveAction action, const QSt
                 // successfully saved the database
                 tempFile.setAutoRemove(false);
                 QFile::setPermissions(filePath, perms);
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
                 // Retain original creation time
                 tempFile.setFileTime(createTime, QFile::FileBirthTime);
-#endif
                 return true;
             } else if (backupFilePath.isEmpty() || !restoreDatabase(filePath, backupFilePath)) {
                 // Failed to copy new database in place, and
diff --git a/src/core/Tools.cpp b/src/core/Tools.cpp
index aa83305c42..c73d5f7d10 100644
--- a/src/core/Tools.cpp
+++ b/src/core/Tools.cpp
@@ -77,7 +77,6 @@ namespace Tools
 #endif
         debugInfo.append("\n");
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 4, 0)
         debugInfo.append(QObject::tr("Operating system: %1\nCPU architecture: %2\nKernel: %3 %4")
                              .arg(QSysInfo::prettyProductName(),
                                   QSysInfo::currentCpuArchitecture(),
@@ -85,7 +84,6 @@ namespace Tools
                                   QSysInfo::kernelVersion()));
 
         debugInfo.append("\n\n");
-#endif
 
         QString extensions;
 #ifdef WITH_XC_AUTOTYPE
diff --git a/src/core/Tools.h b/src/core/Tools.h
index 61d93ffbdb..d9b2023245 100644
--- a/src/core/Tools.h
+++ b/src/core/Tools.h
@@ -88,20 +88,6 @@ namespace Tools
         }
     }
 
-    inline int qtRuntimeVersion()
-    {
-        // Cache the result since the Qt version can't change during
-        // the execution, computing it once will be enough
-        const static int version = []() {
-            const auto sq = QString::fromLatin1(qVersion());
-            return (sq.section(QChar::fromLatin1('.'), 0, 0).toInt() << 16)
-                   + (sq.section(QChar::fromLatin1('.'), 1, 1).toInt() << 8)
-                   + (sq.section(QChar::fromLatin1('.'), 2, 2).toInt());
-        }();
-
-        return version;
-    }
-
     // Checks if all values are found inside the list. Returns a list of values not found.
     template <typename T> QList<T> getMissingValuesFromList(const QList<T>& list, const QList<T>& required)
     {
diff --git a/src/gui/Icons.cpp b/src/gui/Icons.cpp
index 0935bd41e7..117cfadfb2 100644
--- a/src/gui/Icons.cpp
+++ b/src/gui/Icons.cpp
@@ -101,13 +101,11 @@ QIcon Icons::trayIcon(bool unlocked)
 #else
     i = icon(QString("%1-%2%3").arg(applicationIconName(), iconApperance, suffix), false);
 #endif
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     // Set as mask to allow the operating system to recolour the tray icon. This may look weird
     // if we failed to detect the status bar background colour correctly, but it is certainly
     // better than a barely visible icon and even if we did guess correctly, it allows for better
     // integration should the system's preferred colours not be 100% black or white.
     i.setIsMask(true);
-#endif
     return i;
 }
 
@@ -121,11 +119,7 @@ AdaptiveIconEngine::AdaptiveIconEngine(QIcon baseIcon, QColor overrideColor)
 void AdaptiveIconEngine::paint(QPainter* painter, const QRect& rect, QIcon::Mode mode, QIcon::State state)
 {
     // Temporary image canvas to ensure that the background is transparent and alpha blending works.
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     auto scale = painter->device()->devicePixelRatioF();
-#else
-    auto scale = painter->device()->devicePixelRatio();
-#endif
     QImage img(rect.size() * scale, QImage::Format_ARGB32_Premultiplied);
     img.fill(0);
     QPainter p(&img);
@@ -191,9 +185,7 @@ QIcon Icons::icon(const QString& name, bool recolor, const QColor& overrideColor
     icon = QIcon::fromTheme(name);
     if (recolor) {
         icon = QIcon(new AdaptiveIconEngine(icon, overrideColor));
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
         icon.setIsMask(true);
-#endif
     }
 
     m_iconCache.insert(cacheName, icon);
diff --git a/src/gui/MainWindow.cpp b/src/gui/MainWindow.cpp
index 66eb4048bb..7a7bec10b6 100644
--- a/src/gui/MainWindow.cpp
+++ b/src/gui/MainWindow.cpp
@@ -38,7 +38,6 @@
 #include "autotype/AutoType.h"
 #include "core/InactivityTimer.h"
 #include "core/Resources.h"
-#include "core/Tools.h"
 #include "gui/AboutDialog.h"
 #include "gui/ActionCollection.h"
 #include "gui/Icons.h"
@@ -293,7 +292,6 @@ MainWindow::MainWindow()
     connect(m_inactivityTimer, SIGNAL(inactivityDetected()), this, SLOT(lockDatabasesAfterInactivity()));
     applySettingsChanges();
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
     // Qt 5.10 introduced a new "feature" to hide shortcuts in context menus
     // Unfortunately, Qt::AA_DontShowShortcutsInContextMenus is broken, have to manually enable them
     m_ui->actionEntryNew->setShortcutVisibleInContextMenu(true);
@@ -315,7 +313,6 @@ MainWindow::MainWindow()
     m_ui->actionEntryCopyTitle->setShortcutVisibleInContextMenu(true);
     m_ui->actionEntryAddToAgent->setShortcutVisibleInContextMenu(true);
     m_ui->actionEntryRemoveFromAgent->setShortcutVisibleInContextMenu(true);
-#endif
 
     connect(m_ui->menuEntries, SIGNAL(aboutToShow()), SLOT(obtainContextFocusLock()));
     connect(m_ui->menuEntries, SIGNAL(aboutToHide()), SLOT(releaseContextFocusLock()));
@@ -666,15 +663,6 @@ MainWindow::MainWindow()
             MessageWidget::Information,
             -1);
     }
-#elif (QT_VERSION >= QT_VERSION_CHECK(5, 5, 0) && QT_VERSION < QT_VERSION_CHECK(5, 6, 0))
-    if (!config()->get(Config::Messages_Qt55CompatibilityWarning).toBool()) {
-        m_ui->globalMessageWidget->showMessage(
-            tr("WARNING: Your Qt version may cause KeePassXC to crash with an On-Screen Keyboard.\n"
-               "We recommend you use the AppImage available on our downloads page."),
-            MessageWidget::Warning,
-            -1);
-        config()->set(Config::Messages_Qt55CompatibilityWarning, true);
-    }
 #endif
 
     connect(qApp, SIGNAL(anotherInstanceStarted()), this, SLOT(bringToFront()));
@@ -1864,27 +1852,6 @@ void MainWindow::toggleWindow()
         hideWindow();
     } else {
         bringToFront();
-
-#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS) && !defined(QT_NO_DBUS) && (QT_VERSION < QT_VERSION_CHECK(5, 9, 0))
-        // re-register global D-Bus menu (needed on Ubuntu with Unity)
-        // see https://github.com/keepassxreboot/keepassxc/issues/271
-        // and https://bugreports.qt.io/browse/QTBUG-58723
-        // check for !isVisible(), because isNativeMenuBar() does not work with appmenu-qt5
-        static const auto isDesktopSessionUnity = qgetenv("XDG_CURRENT_DESKTOP") == "Unity";
-
-        if (isDesktopSessionUnity && Tools::qtRuntimeVersion() < QT_VERSION_CHECK(5, 9, 0)
-            && !m_ui->menubar->isVisible()) {
-            QDBusMessage msg = QDBusMessage::createMethodCall(QStringLiteral("com.canonical.AppMenu.Registrar"),
-                                                              QStringLiteral("/com/canonical/AppMenu/Registrar"),
-                                                              QStringLiteral("com.canonical.AppMenu.Registrar"),
-                                                              QStringLiteral("RegisterWindow"));
-            QList<QVariant> args;
-            args << QVariant::fromValue(static_cast<uint32_t>(winId()))
-                 << QVariant::fromValue(QDBusObjectPath("/MenuBar/1"));
-            msg.setArguments(args);
-            QDBusConnection::sessionBus().send(msg);
-        }
-#endif
     }
 }
 
@@ -2019,11 +1986,7 @@ void MainWindow::displayDesktopNotification(const QString& msg, QString title, i
         title = BaseWindowTitle;
     }
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 9, 0)
     m_trayIcon->showMessage(title, msg, icons()->applicationIcon(), msTimeoutHint);
-#else
-    m_trayIcon->showMessage(title, msg, QSystemTrayIcon::Information, msTimeoutHint);
-#endif
 }
 
 void MainWindow::restartApp(const QString& message)
diff --git a/src/gui/entry/EntryView.cpp b/src/gui/entry/EntryView.cpp
index 7c5768ef4b..1d7aa02b64 100644
--- a/src/gui/entry/EntryView.cpp
+++ b/src/gui/entry/EntryView.cpp
@@ -570,17 +570,10 @@ void EntryView::startDrag(Qt::DropActions supportedActions)
 
     // Grab the screen pixel ratio where the window resides
     // TODO: Use direct call to screen() when moving to Qt 6
-#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
     auto screen = QGuiApplication::screenAt(window()->geometry().center());
     if (!screen) {
         screen = QGuiApplication::primaryScreen();
     }
-#else
-    auto screen = QGuiApplication::primaryScreen();
-    if (windowHandle()) {
-        screen = windowHandle()->screen();
-    }
-#endif
 
     auto pixelRatio = screen->devicePixelRatio();
 
diff --git a/src/gui/styles/base/BaseStyle.cpp b/src/gui/styles/base/BaseStyle.cpp
index 3b7c562915..7317b00069 100644
--- a/src/gui/styles/base/BaseStyle.cpp
+++ b/src/gui/styles/base/BaseStyle.cpp
@@ -41,10 +41,8 @@
 
 #ifdef Q_OS_MACOS
 #include <QMainWindow>
-#if QT_VERSION >= QT_VERSION_CHECK(5, 9, 0)
 #include <QOperatingSystemVersion>
 #endif
-#endif
 
 #include "gui/Icons.h"
 
@@ -52,15 +50,6 @@ QT_BEGIN_NAMESPACE
 Q_GUI_EXPORT int qt_defaultDpiX();
 QT_END_NAMESPACE
 
-// Redefine Q_FALLTHROUGH for older Qt versions
-#ifndef Q_FALLTHROUGH
-#if (defined(Q_CC_GNU) && Q_CC_GNU >= 700) && !defined(Q_CC_INTEL)
-#define Q_FALLTHROUGH() __attribute__((fallthrough))
-#else
-#define Q_FALLTHROUGH() (void)0
-#endif
-#endif
-
 namespace Phantom
 {
     namespace
@@ -1033,15 +1022,6 @@ namespace Phantom
             painter->restore();
         }
 
-        int fontMetricsWidth(const QFontMetrics& fontMetrics, const QString& text)
-        {
-#if QT_VERSION < QT_VERSION_CHECK(5, 11, 0)
-            return fontMetrics.width(text, text.size(), Qt::TextBypassShaping);
-#else
-            return fontMetrics.horizontalAdvance(text);
-#endif
-        }
-
         // This always draws the arrow with the correct aspect ratio, even if the
         // provided bounding rect is non-square. The base edge of the triangle is
         // snapped to a whole pixel to avoid anti-aliasing making it look soft.
@@ -3886,11 +3866,9 @@ int BaseStyle::pixelMetric(PixelMetric metric, const QStyleOption* option, const
     case PM_DockWidgetTitleBarButtonMargin:
         val = 2;
         break;
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 8, 0))
     case PM_TitleBarButtonSize:
         val = 19;
         break;
-#endif
     case PM_MaximumDragDistance:
         return -1; // Do not dpi-scale because the value is magic
     case PM_TabCloseIndicatorWidth:
@@ -4381,7 +4359,7 @@ QRect BaseStyle::subControlRect(ComplexControl control,
             int textHeight = option->fontMetrics.height();
             // width()/horizontalAdvance() is faster than size() and good enough for
             // us, since we only support a single line of text here anyway.
-            int textWidth = Phantom::fontMetricsWidth(option->fontMetrics, groupBox->text);
+            int textWidth = option->fontMetrics.horizontalAdvance(groupBox->text);
             int indicatorWidth = proxy()->pixelMetric(PM_IndicatorWidth, option, widget);
             int indicatorHeight = proxy()->pixelMetric(PM_IndicatorHeight, option, widget);
             int margin = 0;
@@ -4624,10 +4602,8 @@ int BaseStyle::styleHint(StyleHint hint,
         return Phantom::ShowItemViewDecorationSelected;
     case SH_ItemView_MovementWithoutUpdatingSelection:
         return 1;
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 7, 0))
     case SH_ItemView_ScrollMode:
         return QAbstractItemView::ScrollPerPixel;
-#endif
     case SH_ScrollBar_ContextMenu:
 #ifdef Q_OS_MAC
         return 0;
diff --git a/src/gui/styles/dark/DarkStyle.cpp b/src/gui/styles/dark/DarkStyle.cpp
index 3c4731b2d5..5b021b19ad 100644
--- a/src/gui/styles/dark/DarkStyle.cpp
+++ b/src/gui/styles/dark/DarkStyle.cpp
@@ -51,11 +51,9 @@ QPalette DarkStyle::standardPalette() const
     palette.setColor(QPalette::Inactive, QPalette::Text, QRgb(0xC8C8C6));
     palette.setColor(QPalette::Disabled, QPalette::Text, QRgb(0x707070));
 
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
     palette.setColor(QPalette::Active, QPalette::PlaceholderText, QRgb(0x7D7D82));
     palette.setColor(QPalette::Inactive, QPalette::PlaceholderText, QRgb(0x87888C));
     palette.setColor(QPalette::Disabled, QPalette::PlaceholderText, QRgb(0x737373));
-#endif
 
     palette.setColor(QPalette::Active, QPalette::BrightText, QRgb(0x252627));
     palette.setColor(QPalette::Inactive, QPalette::BrightText, QRgb(0x2D2D2F));
diff --git a/src/gui/styles/light/LightStyle.cpp b/src/gui/styles/light/LightStyle.cpp
index 93cfeb6328..d20b1ef362 100644
--- a/src/gui/styles/light/LightStyle.cpp
+++ b/src/gui/styles/light/LightStyle.cpp
@@ -51,11 +51,9 @@ QPalette LightStyle::standardPalette() const
     palette.setColor(QPalette::Inactive, QPalette::Text, QRgb(0x252528));
     palette.setColor(QPalette::Disabled, QPalette::Text, QRgb(0x8C8C92));
 
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
     palette.setColor(QPalette::Active, QPalette::PlaceholderText, QRgb(0x71727D));
     palette.setColor(QPalette::Inactive, QPalette::PlaceholderText, QRgb(0x878893));
     palette.setColor(QPalette::Disabled, QPalette::PlaceholderText, QRgb(0xA3A4AC));
-#endif
 
     palette.setColor(QPalette::Active, QPalette::BrightText, QRgb(0xF3F3F4));
     palette.setColor(QPalette::Inactive, QPalette::BrightText, QRgb(0xEAEAEB));
diff --git a/src/gui/tag/TagsEdit.cpp b/src/gui/tag/TagsEdit.cpp
index bd4dabb575..6bd0d39dfa 100644
--- a/src/gui/tag/TagsEdit.cpp
+++ b/src/gui/tag/TagsEdit.cpp
@@ -39,12 +39,6 @@
 
 #include <cassert>
 
-#if QT_VERSION < QT_VERSION_CHECK(5, 11, 0)
-#define FONT_METRICS_WIDTH(fmt, ...) fmt.width(__VA_ARGS__)
-#else
-#define FONT_METRICS_WIDTH(fmt, ...) fmt.horizontalAdvance(__VA_ARGS__)
-#endif
-
 namespace
 {
 
@@ -255,7 +249,7 @@ struct TagsEdit::Impl
     {
         for (auto it = range.first; it != range.second; ++it) {
             // calc text rect
-            const auto text_w = FONT_METRICS_WIDTH(fm, it->text);
+            const auto text_w = fm.horizontalAdvance(it->text);
             auto const text_h = fm.height() + fm.leading();
             auto const w = cross_deleter
                                ? tag_inner.left() + tag_inner.right() + tag_cross_padding * 2 + tag_cross_width
@@ -280,7 +274,7 @@ struct TagsEdit::Impl
 
     template <class It> void calcEditorRect(QPoint& lt, size_t& row, QRect r, QFontMetrics const& fm, It it) const
     {
-        auto const text_w = FONT_METRICS_WIDTH(fm, text_layout.text());
+        auto const text_w = fm.horizontalAdvance(text_layout.text());
         auto const text_h = fm.height() + fm.leading();
         auto const w = tag_inner.left() + tag_inner.right();
         auto const h = tag_inner.top() + tag_inner.bottom();
diff --git a/src/main.cpp b/src/main.cpp
index 6c3efea9de..f7d135a5fb 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -52,10 +52,8 @@ int main(int argc, char** argv)
 {
     QT_REQUIRE_VERSION(argc, argv, QT_VERSION_STR)
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
     QGuiApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
-#endif
 #if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0) && defined(Q_OS_WIN)
     QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
 #endif
@@ -172,9 +170,7 @@ int main(int argc, char** argv)
     // Apply the configured theme before creating any GUI elements
     app.applyTheme();
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
     QGuiApplication::setDesktopFileName(app.property("KPXC_QUALIFIED_APPNAME").toString() + QStringLiteral(".desktop"));
-#endif
 
     Application::bootstrap(config()->get(Config::GUI_Language).toString());
 
diff --git a/tests/gui/TestGui.cpp b/tests/gui/TestGui.cpp
index 694fbf36cd..aaf0611bfe 100644
--- a/tests/gui/TestGui.cpp
+++ b/tests/gui/TestGui.cpp
@@ -75,10 +75,8 @@
 
 int main(int argc, char* argv[])
 {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
     QGuiApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
-#endif
     Application app(argc, argv);
     app.setApplicationName("KeePassXC");
     app.setApplicationVersion(KEEPASSXC_VERSION);
diff --git a/tests/gui/TestGuiBrowser.cpp b/tests/gui/TestGuiBrowser.cpp
index 68698b5fb8..ba45c1f1a9 100644
--- a/tests/gui/TestGuiBrowser.cpp
+++ b/tests/gui/TestGuiBrowser.cpp
@@ -41,10 +41,8 @@
 
 int main(int argc, char* argv[])
 {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
     QGuiApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
-#endif
     Application app(argc, argv);
     app.setApplicationName("KeePassXC");
     app.setApplicationVersion(KEEPASSXC_VERSION);
diff --git a/tests/gui/TestGuiFdoSecrets.cpp b/tests/gui/TestGuiFdoSecrets.cpp
index c690dedf73..ba8b8fbdab 100644
--- a/tests/gui/TestGuiFdoSecrets.cpp
+++ b/tests/gui/TestGuiFdoSecrets.cpp
@@ -46,10 +46,8 @@
 
 int main(int argc, char* argv[])
 {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
     QGuiApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
-#endif
     Application app(argc, argv);
     app.setApplicationName("KeePassXC");
     app.setApplicationVersion(KEEPASSXC_VERSION);