diff --git a/autotests/kdeplatformtheme_unittest.cpp b/autotests/kdeplatformtheme_unittest.cpp
--- a/autotests/kdeplatformtheme_unittest.cpp
+++ b/autotests/kdeplatformtheme_unittest.cpp
@@ -80,7 +80,7 @@
 
     }
 
-    bool eventFilter(QObject *, QEvent *e) Q_DECL_OVERRIDE
+    bool eventFilter(QObject *, QEvent *e) override
     {
         if (e->type() == m_type) {
             gotEvent = true;
diff --git a/autotests/kfontsettingsdata_unittest.cpp b/autotests/kfontsettingsdata_unittest.cpp
--- a/autotests/kfontsettingsdata_unittest.cpp
+++ b/autotests/kfontsettingsdata_unittest.cpp
@@ -60,7 +60,7 @@
 {
     Q_OBJECT
 public:
-    bool event(QEvent *e) Q_DECL_OVERRIDE
+    bool event(QEvent *e) override
     {
         if (e->type() == QEvent::ApplicationFontChange) {
             m_appChangedFont = true;
diff --git a/src/platformtheme/kdeplatformfiledialogbase_p.h b/src/platformtheme/kdeplatformfiledialogbase_p.h
--- a/src/platformtheme/kdeplatformfiledialogbase_p.h
+++ b/src/platformtheme/kdeplatformfiledialogbase_p.h
@@ -55,7 +55,7 @@
     void filterSelected(const QString &filter);
 
 protected:
-    void closeEvent(QCloseEvent *e) Q_DECL_OVERRIDE;
+    void closeEvent(QCloseEvent *e) override;
     QDialogButtonBox *m_buttons;
     QTimer m_timer;
 };
diff --git a/src/platformtheme/kdeplatformfiledialoghelper.h b/src/platformtheme/kdeplatformfiledialoghelper.h
--- a/src/platformtheme/kdeplatformfiledialoghelper.h
+++ b/src/platformtheme/kdeplatformfiledialoghelper.h
@@ -33,17 +33,17 @@
     friend class KDEPlatformFileDialogHelper;
 
     explicit KDEPlatformFileDialog();
-    QUrl directory() Q_DECL_OVERRIDE;
-    void selectMimeTypeFilter(const QString &filter) Q_DECL_OVERRIDE;
-    void selectNameFilter(const QString &filter) Q_DECL_OVERRIDE;
-    void setDirectory(const QUrl &directory) Q_DECL_OVERRIDE;
-    void selectFile(const QUrl &filename) Q_DECL_OVERRIDE;
+    QUrl directory() override;
+    void selectMimeTypeFilter(const QString &filter) override;
+    void selectNameFilter(const QString &filter) override;
+    void setDirectory(const QUrl &directory) override;
+    void selectFile(const QUrl &filename) override;
     void setViewMode(QFileDialogOptions::ViewMode view);
     void setFileMode(QFileDialogOptions::FileMode mode);
     void setCustomLabel(QFileDialogOptions::DialogLabel label, const QString & text);
-    QString selectedMimeTypeFilter() Q_DECL_OVERRIDE;
-    QString selectedNameFilter() Q_DECL_OVERRIDE;
-    QList<QUrl> selectedFiles() Q_DECL_OVERRIDE;
+    QString selectedMimeTypeFilter() override;
+    QString selectedNameFilter() override;
+    QList<QUrl> selectedFiles() override;
 
 protected:
     KFileWidget *m_fileWidget;
@@ -58,23 +58,23 @@
 
     void initializeDialog();
 
-    bool defaultNameFilterDisables() const Q_DECL_OVERRIDE;
-    QUrl directory() const Q_DECL_OVERRIDE;
-    QList<QUrl> selectedFiles() const Q_DECL_OVERRIDE;
+    bool defaultNameFilterDisables() const override;
+    QUrl directory() const override;
+    QList<QUrl> selectedFiles() const override;
 #if QT_VERSION >= QT_VERSION_CHECK(5, 9, 0)
-    QString selectedMimeTypeFilter() const Q_DECL_OVERRIDE;
-    void selectMimeTypeFilter(const QString &filter) Q_DECL_OVERRIDE;
+    QString selectedMimeTypeFilter() const override;
+    void selectMimeTypeFilter(const QString &filter) override;
 #endif
-    QString selectedNameFilter() const Q_DECL_OVERRIDE;
-    void selectNameFilter(const QString &filter) Q_DECL_OVERRIDE;
-    void selectFile(const QUrl &filename) Q_DECL_OVERRIDE;
-    void setFilter() Q_DECL_OVERRIDE;
-    void setDirectory(const QUrl &directory) Q_DECL_OVERRIDE;
-    bool isSupportedUrl(const QUrl& url) const Q_DECL_OVERRIDE;
+    QString selectedNameFilter() const override;
+    void selectNameFilter(const QString &filter) override;
+    void selectFile(const QUrl &filename) override;
+    void setFilter() override;
+    void setDirectory(const QUrl &directory) override;
+    bool isSupportedUrl(const QUrl& url) const override;
 
-    void exec() Q_DECL_OVERRIDE;
-    void hide() Q_DECL_OVERRIDE;
-    bool show(Qt::WindowFlags windowFlags, Qt::WindowModality windowModality, QWindow *parent) Q_DECL_OVERRIDE;
+    void exec() override;
+    void hide() override;
+    bool show(Qt::WindowFlags windowFlags, Qt::WindowModality windowModality, QWindow *parent) override;
 
 private Q_SLOTS:
     void saveSize();
diff --git a/src/platformtheme/kdeplatformsystemtrayicon.h b/src/platformtheme/kdeplatformsystemtrayicon.h
--- a/src/platformtheme/kdeplatformsystemtrayicon.h
+++ b/src/platformtheme/kdeplatformsystemtrayicon.h
@@ -33,20 +33,20 @@
     Q_OBJECT
 public:
     SystemTrayMenu();
-    ~SystemTrayMenu() Q_DECL_OVERRIDE;
-    void insertMenuItem(QPlatformMenuItem *menuItem, QPlatformMenuItem *before) Q_DECL_OVERRIDE;
-    QPlatformMenuItem *menuItemAt(int position) const Q_DECL_OVERRIDE;
-    QPlatformMenuItem *menuItemForTag(quintptr tag) const Q_DECL_OVERRIDE;
-    void removeMenuItem(QPlatformMenuItem *menuItem) Q_DECL_OVERRIDE;
-    void setEnabled(bool enabled) Q_DECL_OVERRIDE;
-    void setIcon(const QIcon &icon) Q_DECL_OVERRIDE;
-    void setTag(quintptr tag) Q_DECL_OVERRIDE;
-    void setText(const QString &text) Q_DECL_OVERRIDE;
-    void setVisible(bool visible) Q_DECL_OVERRIDE;
-    void syncMenuItem(QPlatformMenuItem *menuItem) Q_DECL_OVERRIDE;
-    void syncSeparatorsCollapsible(bool enable) Q_DECL_OVERRIDE;
-    quintptr tag() const Q_DECL_OVERRIDE;
-    QPlatformMenuItem *createMenuItem() const Q_DECL_OVERRIDE;
+    ~SystemTrayMenu() override;
+    void insertMenuItem(QPlatformMenuItem *menuItem, QPlatformMenuItem *before) override;
+    QPlatformMenuItem *menuItemAt(int position) const override;
+    QPlatformMenuItem *menuItemForTag(quintptr tag) const override;
+    void removeMenuItem(QPlatformMenuItem *menuItem) override;
+    void setEnabled(bool enabled) override;
+    void setIcon(const QIcon &icon) override;
+    void setTag(quintptr tag) override;
+    void setText(const QString &text) override;
+    void setVisible(bool visible) override;
+    void syncMenuItem(QPlatformMenuItem *menuItem) override;
+    void syncSeparatorsCollapsible(bool enable) override;
+    quintptr tag() const override;
+    QPlatformMenuItem *createMenuItem() const override;
 
     QMenu *menu() const;
 
@@ -61,21 +61,21 @@
     Q_OBJECT
 public:
     SystemTrayMenuItem();
-    ~SystemTrayMenuItem() Q_DECL_OVERRIDE;
-    void setCheckable(bool checkable) Q_DECL_OVERRIDE;
-    void setChecked(bool isChecked) Q_DECL_OVERRIDE;
-    void setEnabled(bool enabled) Q_DECL_OVERRIDE;
-    void setFont(const QFont &font) Q_DECL_OVERRIDE;
-    void setIcon(const QIcon &icon) Q_DECL_OVERRIDE;
-    void setIsSeparator(bool isSeparator) Q_DECL_OVERRIDE;
-    void setMenu(QPlatformMenu *menu) Q_DECL_OVERRIDE;
-    void setRole(MenuRole role) Q_DECL_OVERRIDE;
-    void setShortcut(const QKeySequence &shortcut) Q_DECL_OVERRIDE;
-    void setTag(quintptr tag) Q_DECL_OVERRIDE;
-    void setText(const QString &text) Q_DECL_OVERRIDE;
-    void setVisible(bool isVisible) Q_DECL_OVERRIDE;
-    quintptr tag() const Q_DECL_OVERRIDE;
-    void setIconSize(int size) Q_DECL_OVERRIDE;
+    ~SystemTrayMenuItem() override;
+    void setCheckable(bool checkable) override;
+    void setChecked(bool isChecked) override;
+    void setEnabled(bool enabled) override;
+    void setFont(const QFont &font) override;
+    void setIcon(const QIcon &icon) override;
+    void setIsSeparator(bool isSeparator) override;
+    void setMenu(QPlatformMenu *menu) override;
+    void setRole(MenuRole role) override;
+    void setShortcut(const QKeySequence &shortcut) override;
+    void setTag(quintptr tag) override;
+    void setText(const QString &text) override;
+    void setVisible(bool isVisible) override;
+    quintptr tag() const override;
+    void setIconSize(int size) override;
 
     QAction *action() const;
 
@@ -88,21 +88,21 @@
 {
 public:
     KDEPlatformSystemTrayIcon();
-    ~KDEPlatformSystemTrayIcon() Q_DECL_OVERRIDE;
+    ~KDEPlatformSystemTrayIcon() override;
 
-    void init() Q_DECL_OVERRIDE;
-    void cleanup() Q_DECL_OVERRIDE;
-    void updateIcon(const QIcon &icon) Q_DECL_OVERRIDE;
-    void updateToolTip(const QString &tooltip) Q_DECL_OVERRIDE;
-    void updateMenu(QPlatformMenu *menu) Q_DECL_OVERRIDE;
-    QRect geometry() const Q_DECL_OVERRIDE;
+    void init() override;
+    void cleanup() override;
+    void updateIcon(const QIcon &icon) override;
+    void updateToolTip(const QString &tooltip) override;
+    void updateMenu(QPlatformMenu *menu) override;
+    QRect geometry() const override;
     void showMessage(const QString &title, const QString &msg,
-                     const QIcon &icon, MessageIcon iconType, int secs) Q_DECL_OVERRIDE;
+                     const QIcon &icon, MessageIcon iconType, int secs) override;
 
-    bool isSystemTrayAvailable() const Q_DECL_OVERRIDE;
-    bool supportsMessages() const Q_DECL_OVERRIDE;
+    bool isSystemTrayAvailable() const override;
+    bool supportsMessages() const override;
 
-    QPlatformMenu *createMenu() const Q_DECL_OVERRIDE;
+    QPlatformMenu *createMenu() const override;
 
 private:
     KStatusNotifierItem *m_sni;
diff --git a/src/platformtheme/kdeplatformtheme.h b/src/platformtheme/kdeplatformtheme.h
--- a/src/platformtheme/kdeplatformtheme.h
+++ b/src/platformtheme/kdeplatformtheme.h
@@ -42,7 +42,7 @@
     KdePlatformTheme();
     ~KdePlatformTheme();
 
-    QVariant themeHint(ThemeHint hint) const Q_DECL_OVERRIDE;
+    QVariant themeHint(ThemeHint hint) const override;
 #if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
     QIcon fileIcon(const QFileInfo &fileInfo,
                            QPlatformTheme::IconOptions iconOptions) const override;
@@ -53,20 +53,20 @@
     QIcon fileIcon(const QFileInfo &fileInfo,
                            QPlatformTheme::IconOptions iconOptions) const;
 #endif
-    const QPalette *palette(Palette type = SystemPalette) const Q_DECL_OVERRIDE;
-    const QFont *font(Font type) const Q_DECL_OVERRIDE;
-    QIconEngine *createIconEngine(const QString &iconName) const Q_DECL_OVERRIDE;
-    QList<QKeySequence> keyBindings(QKeySequence::StandardKey key) const Q_DECL_OVERRIDE;
+    const QPalette *palette(Palette type = SystemPalette) const override;
+    const QFont *font(Font type) const override;
+    QIconEngine *createIconEngine(const QString &iconName) const override;
+    QList<QKeySequence> keyBindings(QKeySequence::StandardKey key) const override;
 
-    QPlatformDialogHelper *createPlatformDialogHelper(DialogType type) const Q_DECL_OVERRIDE;
-    bool usePlatformNativeDialog(DialogType type) const Q_DECL_OVERRIDE;
+    QPlatformDialogHelper *createPlatformDialogHelper(DialogType type) const override;
+    bool usePlatformNativeDialog(DialogType type) const override;
 
-    QString standardButtonText(int button) const Q_DECL_OVERRIDE;
+    QString standardButtonText(int button) const override;
 
-    QPlatformSystemTrayIcon *createPlatformSystemTrayIcon() const Q_DECL_OVERRIDE;
+    QPlatformSystemTrayIcon *createPlatformSystemTrayIcon() const override;
 
 #if QT_VERSION >= QT_VERSION_CHECK(5,7,0)
-    QPlatformMenuBar *createPlatformMenuBar() const Q_DECL_OVERRIDE;
+    QPlatformMenuBar *createPlatformMenuBar() const override;
 #endif
 
 private:
diff --git a/src/platformtheme/kdirselectdialog_p.h b/src/platformtheme/kdirselectdialog_p.h
--- a/src/platformtheme/kdirselectdialog_p.h
+++ b/src/platformtheme/kdirselectdialog_p.h
@@ -97,28 +97,28 @@
      */
     QUrl startDir() const;
 
-    QUrl directory() Q_DECL_OVERRIDE;
-    void selectMimeTypeFilter(const QString &filter) Q_DECL_OVERRIDE;
-    void selectNameFilter(const QString &filter) Q_DECL_OVERRIDE;
-    void setDirectory(const QUrl &directory) Q_DECL_OVERRIDE;
-    void selectFile(const QUrl &filename) Q_DECL_OVERRIDE;
-    QString selectedMimeTypeFilter() Q_DECL_OVERRIDE;
-    QString selectedNameFilter() Q_DECL_OVERRIDE;
-    QList<QUrl> selectedFiles() Q_DECL_OVERRIDE;
+    QUrl directory() override;
+    void selectMimeTypeFilter(const QString &filter) override;
+    void selectNameFilter(const QString &filter) override;
+    void setDirectory(const QUrl &directory) override;
+    void selectFile(const QUrl &filename) override;
+    QString selectedMimeTypeFilter() override;
+    QString selectedNameFilter() override;
+    QList<QUrl> selectedFiles() override;
 
 public Q_SLOTS:
     /**
      * Sets the current @p url in the dialog.
      */
     void setCurrentUrl(const QUrl &url);
 
 protected:
-    void accept() Q_DECL_OVERRIDE;
+    void accept() override;
 
     /**
      * Reimplemented for saving the dialog geometry.
      */
-    void hideEvent(QHideEvent *event) Q_DECL_OVERRIDE;
+    void hideEvent(QHideEvent *event) override;
 
 private:
     class Private;
diff --git a/src/platformtheme/kfiletreeview_p.h b/src/platformtheme/kfiletreeview_p.h
--- a/src/platformtheme/kfiletreeview_p.h
+++ b/src/platformtheme/kfiletreeview_p.h
@@ -73,7 +73,7 @@
     /**
      * @reimplemented
      */
-    QSize sizeHint() const Q_DECL_OVERRIDE;
+    QSize sizeHint() const override;
 
 public Q_SLOTS:
     /**
@@ -114,7 +114,7 @@
 
 protected:
     using QTreeView::currentChanged;
-    void contextMenuEvent(QContextMenuEvent *) Q_DECL_OVERRIDE;
+    void contextMenuEvent(QContextMenuEvent *) override;
 
 private:
     class Private;
diff --git a/src/platformtheme/kwaylandintegration.h b/src/platformtheme/kwaylandintegration.h
--- a/src/platformtheme/kwaylandintegration.h
+++ b/src/platformtheme/kwaylandintegration.h
@@ -42,7 +42,7 @@
 
     void setWindowProperty(QWindow *window, const QByteArray &name, const QByteArray &value);
 
-    bool eventFilter(QObject *watched, QEvent *event) Q_DECL_OVERRIDE;
+    bool eventFilter(QObject *watched, QEvent *event) override;
 
 private:
     void shellSurfaceCreated(QWindow *w);
diff --git a/src/platformtheme/main.cpp b/src/platformtheme/main.cpp
--- a/src/platformtheme/main.cpp
+++ b/src/platformtheme/main.cpp
@@ -30,7 +30,7 @@
     KdePlatformThemePlugin(QObject *parent = 0)
         : QPlatformThemePlugin(parent) {}
 
-    QPlatformTheme *create(const QString &key, const QStringList &paramList) Q_DECL_OVERRIDE
+    QPlatformTheme *create(const QString &key, const QStringList &paramList) override
     {
         Q_UNUSED(key)
         Q_UNUSED(paramList)
diff --git a/src/platformtheme/qdbusmenubar_p.h b/src/platformtheme/qdbusmenubar_p.h
--- a/src/platformtheme/qdbusmenubar_p.h
+++ b/src/platformtheme/qdbusmenubar_p.h
@@ -79,12 +79,12 @@
     QDBusMenuBar();
     virtual ~QDBusMenuBar();
 
-    void insertMenu(QPlatformMenu *menu, QPlatformMenu *before) Q_DECL_OVERRIDE;
-    void removeMenu(QPlatformMenu *menu) Q_DECL_OVERRIDE;
-    void syncMenu(QPlatformMenu *menu) Q_DECL_OVERRIDE;
-    void handleReparent(QWindow *newParentWindow) Q_DECL_OVERRIDE;
-    QPlatformMenu *menuForTag(quintptr tag) const Q_DECL_OVERRIDE;
-    QPlatformMenu *createMenu() const Q_DECL_OVERRIDE;
+    void insertMenu(QPlatformMenu *menu, QPlatformMenu *before) override;
+    void removeMenu(QPlatformMenu *menu) override;
+    void syncMenu(QPlatformMenu *menu) override;
+    void handleReparent(QWindow *newParentWindow) override;
+    QPlatformMenu *menuForTag(quintptr tag) const override;
+    QPlatformMenu *createMenu() const override;
 
     QWindow *window() const { return m_window; }
     QString objectPath() const { return m_objectPath; }
diff --git a/src/platformtheme/x11integration.h b/src/platformtheme/x11integration.h
--- a/src/platformtheme/x11integration.h
+++ b/src/platformtheme/x11integration.h
@@ -37,7 +37,7 @@
 
     void setWindowProperty(QWindow *window, const QByteArray &name, const QByteArray &value);
 
-    bool eventFilter(QObject *watched, QEvent *event) Q_DECL_OVERRIDE;
+    bool eventFilter(QObject *watched, QEvent *event) override;
 
 private:
     void installColorScheme(QWindow *w);