diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dbackingstore.h b/src/plugins/platforms/direct2d/qwindowsdirect2dbackingstore.h
index 1c7f65a12d..08bfaa1240 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dbackingstore.h
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dbackingstore.h
@@ -48,8 +48,8 @@ public:
     QWindowsDirect2DBackingStore(QWindow *window);
     ~QWindowsDirect2DBackingStore();
 
-    void beginPaint(const QRegion &);
-    void endPaint();
+    void beginPaint(const QRegion &) Q_DECL_OVERRIDE;
+    void endPaint() Q_DECL_OVERRIDE;
 
     QPaintDevice *paintDevice() Q_DECL_OVERRIDE;
     void flush(QWindow *targetWindow, const QRegion &region, const QPoint &offset) Q_DECL_OVERRIDE;
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dplatformpixmap.h b/src/plugins/platforms/direct2d/qwindowsdirect2dplatformpixmap.h
index 5720f84853..a9591a493a 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dplatformpixmap.h
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dplatformpixmap.h
@@ -54,8 +54,7 @@ public:
     ~QWindowsDirect2DPlatformPixmap();
 
     void resize(int width, int height) Q_DECL_OVERRIDE;
-    virtual void fromImage(const QImage &image,
-                           Qt::ImageConversionFlags flags);
+    void fromImage(const QImage &image, Qt::ImageConversionFlags flags) Q_DECL_OVERRIDE;
 
     int metric(QPaintDevice::PaintDeviceMetric metric) const Q_DECL_OVERRIDE;
     void fill(const QColor &color) Q_DECL_OVERRIDE;
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index b983ba3354..9211fd1320 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -876,12 +876,12 @@ public:
 
     inline static QWindowsNativeFileDialogBase *create(QFileDialogOptions::AcceptMode am, const QWindowsFileDialogSharedData &data);
 
-    virtual void setWindowTitle(const QString &title);
+    void setWindowTitle(const QString &title) Q_DECL_OVERRIDE;
     inline void setMode(QFileDialogOptions::FileMode mode, QFileDialogOptions::AcceptMode acceptMode, QFileDialogOptions::FileDialogOptions options);
     inline void setDirectory(const QUrl &directory);
     inline void updateDirectory() { setDirectory(m_data.directory()); }
     inline QString directory() const;
-    virtual void doExec(HWND owner = 0);
+    void doExec(HWND owner = 0) Q_DECL_OVERRIDE;
     virtual void setNameFilters(const QStringList &f);
     inline void selectNameFilter(const QString &filter);
     inline void updateSelectedNameFilter() { selectNameFilter(m_data.selectedNameFilter()); }
@@ -910,7 +910,7 @@ signals:
     void filterSelected(const QString & filter);
 
 public slots:
-    virtual void close();
+    void close() Q_DECL_OVERRIDE;
 
 protected:
     explicit QWindowsNativeFileDialogBase(const QWindowsFileDialogSharedData &data);
@@ -1460,9 +1460,9 @@ class QWindowsNativeSaveFileDialog : public QWindowsNativeFileDialogBase
 public:
     explicit QWindowsNativeSaveFileDialog(const QWindowsFileDialogSharedData &data)
         : QWindowsNativeFileDialogBase(data) {}
-    virtual void setNameFilters(const QStringList &f);
-    virtual QList<QUrl> selectedFiles() const;
-    virtual QList<QUrl> dialogResult() const;
+    void setNameFilters(const QStringList &f) Q_DECL_OVERRIDE;
+    QList<QUrl> selectedFiles() const Q_DECL_OVERRIDE;
+    QList<QUrl> dialogResult() const Q_DECL_OVERRIDE;
 };
 
 // Return the first suffix from the name filter "Foo files (*.foo;*.bar)" -> "foo".
@@ -1531,8 +1531,8 @@ class QWindowsNativeOpenFileDialog : public QWindowsNativeFileDialogBase
 public:
     explicit QWindowsNativeOpenFileDialog(const QWindowsFileDialogSharedData &data) :
         QWindowsNativeFileDialogBase(data) {}
-    virtual QList<QUrl> selectedFiles() const;
-    virtual QList<QUrl> dialogResult() const;
+    QList<QUrl> selectedFiles() const Q_DECL_OVERRIDE;
+    QList<QUrl> dialogResult() const Q_DECL_OVERRIDE;
 
 private:
     inline IFileOpenDialog *openFileDialog() const
@@ -1616,7 +1616,7 @@ public:
     virtual QString selectedNameFilter() const Q_DECL_OVERRIDE;
 
 private:
-    virtual QWindowsNativeDialogBase *createNativeDialog();
+    QWindowsNativeDialogBase *createNativeDialog() Q_DECL_OVERRIDE;
     inline QWindowsNativeFileDialogBase *nativeFileDialog() const
         { return static_cast<QWindowsNativeFileDialogBase *>(nativeDialog()); }
 
@@ -1744,14 +1744,13 @@ public:
 
     static QWindowsXpNativeFileDialog *create(const OptionsPtr &options, const QWindowsFileDialogSharedData &data);
 
-    virtual void setWindowTitle(const QString &t) { m_title =  t; }
-    virtual void doExec(HWND owner = 0);
-    virtual QPlatformDialogHelper::DialogCode result() const { return m_result; }
+    void setWindowTitle(const QString &t) Q_DECL_OVERRIDE { m_title =  t; }
+    void doExec(HWND owner = 0) Q_DECL_OVERRIDE;
 
     int existingDirCallback(HWND hwnd, UINT uMsg, LPARAM lParam);
 
 public slots:
-    virtual void close() {}
+     void close() Q_DECL_OVERRIDE {}
 
 private:
     typedef BOOL (APIENTRY *PtrGetOpenFileNameW)(LPOPENFILENAMEW);
@@ -1987,19 +1986,19 @@ class QWindowsXpFileDialogHelper : public QWindowsDialogHelperBase<QPlatformFile
 {
 public:
     QWindowsXpFileDialogHelper() {}
-    virtual bool supportsNonModalDialog(const QWindow * /* parent */ = 0) const { return false; }
-    virtual bool defaultNameFilterDisables() const
+    bool supportsNonModalDialog(const QWindow * /* parent */ = 0) const Q_DECL_OVERRIDE { return false; }
+    bool defaultNameFilterDisables() const Q_DECL_OVERRIDE
         { return true; }
-    virtual void setDirectory(const QUrl &directory) Q_DECL_OVERRIDE;
-    virtual QUrl directory() const Q_DECL_OVERRIDE;
-    virtual void selectFile(const QUrl &url) Q_DECL_OVERRIDE;
-    virtual QList<QUrl> selectedFiles() const Q_DECL_OVERRIDE;
-    virtual void setFilter() Q_DECL_OVERRIDE {}
-    virtual void selectNameFilter(const QString &) Q_DECL_OVERRIDE;
-    virtual QString selectedNameFilter() const Q_DECL_OVERRIDE;
+    void setDirectory(const QUrl &directory) Q_DECL_OVERRIDE;
+    QUrl directory() const Q_DECL_OVERRIDE;
+    void selectFile(const QUrl &url) Q_DECL_OVERRIDE;
+    QList<QUrl> selectedFiles() const Q_DECL_OVERRIDE;
+    void setFilter() Q_DECL_OVERRIDE {}
+    void selectNameFilter(const QString &) Q_DECL_OVERRIDE;
+    QString selectedNameFilter() const Q_DECL_OVERRIDE;
 
 private:
-    virtual QWindowsNativeDialogBase *createNativeDialog();
+    QWindowsNativeDialogBase *createNativeDialog() Q_DECL_OVERRIDE;
     inline QWindowsXpNativeFileDialog *nativeFileDialog() const
         { return static_cast<QWindowsXpNativeFileDialog *>(nativeDialog()); }
 
@@ -2073,14 +2072,13 @@ public:
 
     explicit QWindowsNativeColorDialog(const SharedPointerColor &color);
 
-    virtual void setWindowTitle(const QString &) {}
-    virtual QPlatformDialogHelper::DialogCode result() const { return m_code; }
+    void setWindowTitle(const QString &) Q_DECL_OVERRIDE {}
 
 public slots:
-    virtual void close() {}
+    void close() Q_DECL_OVERRIDE {}
 
 private:
-    virtual void doExec(HWND owner = 0);
+    void doExec(HWND owner = 0) Q_DECL_OVERRIDE;
 
     COLORREF m_customColors[CustomColorCount];
     QPlatformDialogHelper::DialogCode m_code;
diff --git a/src/plugins/platforms/windows/qwindowsdrag.cpp b/src/plugins/platforms/windows/qwindowsdrag.cpp
index 021058fa33..16079576a2 100644
--- a/src/plugins/platforms/windows/qwindowsdrag.cpp
+++ b/src/plugins/platforms/windows/qwindowsdrag.cpp
@@ -78,7 +78,7 @@ public:
     void setPixmap(const QPixmap &p);
 
 protected:
-    void paintEvent(QPaintEvent *)
+    void paintEvent(QPaintEvent *) Q_DECL_OVERRIDE
     {
         QPainter painter(this);
         painter.drawPixmap(0, 0, m_pixmap);
diff --git a/src/plugins/platforms/windows/qwindowsfontdatabase_ft.h b/src/plugins/platforms/windows/qwindowsfontdatabase_ft.h
index ad5c005ffa..f65dc38801 100644
--- a/src/plugins/platforms/windows/qwindowsfontdatabase_ft.h
+++ b/src/plugins/platforms/windows/qwindowsfontdatabase_ft.h
@@ -43,12 +43,15 @@ QT_BEGIN_NAMESPACE
 class QWindowsFontDatabaseFT : public QBasicFontDatabase
 {
 public:
-    void populateFontDatabase();
+    void populateFontDatabase() Q_DECL_OVERRIDE;
     void populateFamily(const QString &familyName) Q_DECL_OVERRIDE;
-    QFontEngine *fontEngine(const QFontDef &fontDef, void *handle);
-    QFontEngine *fontEngine(const QByteArray &fontData, qreal pixelSize, QFont::HintingPreference hintingPreference);
+    QFontEngine *fontEngine(const QFontDef &fontDef, void *handle) Q_DECL_OVERRIDE;
+    QFontEngine *fontEngine(const QByteArray &fontData, qreal pixelSize,
+                            QFont::HintingPreference hintingPreference) Q_DECL_OVERRIDE;
 
-    QStringList fallbacksForFamily(const QString &family, QFont::Style style, QFont::StyleHint styleHint, QChar::Script script) const;
+    QStringList fallbacksForFamily(const QString &family, QFont::Style style,
+                                   QFont::StyleHint styleHint,
+                                   QChar::Script script) const Q_DECL_OVERRIDE;
 
     QString fontDir() const Q_DECL_OVERRIDE;
     QFont defaultFont() const Q_DECL_OVERRIDE;
diff --git a/src/plugins/platforms/windows/qwindowsfontengine.h b/src/plugins/platforms/windows/qwindowsfontengine.h
index 409b44264e..5317368455 100644
--- a/src/plugins/platforms/windows/qwindowsfontengine.h
+++ b/src/plugins/platforms/windows/qwindowsfontengine.h
@@ -84,7 +84,7 @@ public:
 
     void addOutlineToPath(qreal x, qreal y, const QGlyphLayout &glyphs, QPainterPath *path, QTextItem::RenderFlags flags) Q_DECL_OVERRIDE;
     virtual void addGlyphsToPath(glyph_t *glyphs, QFixedPoint *positions, int nglyphs,
-                         QPainterPath *path, QTextItem::RenderFlags flags);
+                         QPainterPath *path, QTextItem::RenderFlags flags) Q_DECL_OVERRIDE;
 
     HGDIOBJ selectDesignFont() const;
 
diff --git a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h
index cee8691d69..07e040ed33 100644
--- a/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h
+++ b/src/plugins/platforms/windows/qwindowsfontenginedirectwrite.h
@@ -61,35 +61,37 @@ public:
 
     void initFontInfo(const QFontDef &request, int dpi, IDWriteFont *font);
 
-    QFixed lineThickness() const;
-    QFixed underlinePosition() const;
-    bool getSfntTableData(uint tag, uchar *buffer, uint *length) const;
-    QFixed emSquareSize() const;
+    QFixed lineThickness() const Q_DECL_OVERRIDE;
+    QFixed underlinePosition() const Q_DECL_OVERRIDE;
+    bool getSfntTableData(uint tag, uchar *buffer, uint *length) const Q_DECL_OVERRIDE;
+    QFixed emSquareSize() const Q_DECL_OVERRIDE;
 
     glyph_t glyphIndex(uint ucs4) const Q_DECL_OVERRIDE;
-    bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs, ShaperFlags flags) const;
-    void recalcAdvances(QGlyphLayout *glyphs, ShaperFlags) const;
+    bool stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs, int *nglyphs,
+                      ShaperFlags flags) const Q_DECL_OVERRIDE;
+    void recalcAdvances(QGlyphLayout *glyphs, ShaperFlags) const Q_DECL_OVERRIDE;
 
     void addGlyphsToPath(glyph_t *glyphs, QFixedPoint *positions, int nglyphs,
-                         QPainterPath *path, QTextItem::RenderFlags flags);
+                         QPainterPath *path, QTextItem::RenderFlags flags) Q_DECL_OVERRIDE;
 
-    glyph_metrics_t boundingBox(const QGlyphLayout &glyphs);
-    glyph_metrics_t boundingBox(glyph_t g);
-    glyph_metrics_t alphaMapBoundingBox(glyph_t glyph, QFixed, const QTransform &matrix, GlyphFormat);
+    glyph_metrics_t boundingBox(const QGlyphLayout &glyphs) Q_DECL_OVERRIDE;
+    glyph_metrics_t boundingBox(glyph_t g) Q_DECL_OVERRIDE;
+    glyph_metrics_t alphaMapBoundingBox(glyph_t glyph, QFixed,
+                                        const QTransform &matrix, GlyphFormat) Q_DECL_OVERRIDE;
 
-    QFixed ascent() const;
-    QFixed descent() const;
-    QFixed leading() const;
-    QFixed xHeight() const;
-    qreal maxCharWidth() const;
+    QFixed ascent() const Q_DECL_OVERRIDE;
+    QFixed descent() const Q_DECL_OVERRIDE;
+    QFixed leading() const Q_DECL_OVERRIDE;
+    QFixed xHeight() const Q_DECL_OVERRIDE;
+    qreal maxCharWidth() const Q_DECL_OVERRIDE;
 
-    bool supportsSubPixelPositions() const;
+    bool supportsSubPixelPositions() const Q_DECL_OVERRIDE;
 
-    QImage alphaMapForGlyph(glyph_t glyph, QFixed subPixelPosition);
-    QImage alphaMapForGlyph(glyph_t glyph, QFixed subPixelPosition, const QTransform &t);
-    QImage alphaRGBMapForGlyph(glyph_t t, QFixed subPixelPosition, const QTransform &xform);
+    QImage alphaMapForGlyph(glyph_t glyph, QFixed subPixelPosition) Q_DECL_OVERRIDE;
+    QImage alphaMapForGlyph(glyph_t glyph, QFixed subPixelPosition, const QTransform &t) Q_DECL_OVERRIDE;
+    QImage alphaRGBMapForGlyph(glyph_t t, QFixed subPixelPosition, const QTransform &xform) Q_DECL_OVERRIDE;
 
-    QFontEngine *cloneWithSize(qreal pixelSize) const;
+    QFontEngine *cloneWithSize(qreal pixelSize) const Q_DECL_OVERRIDE;
 
     const QSharedPointer<QWindowsFontEngineData> &fontEngineData() const { return m_fontEngineData; }
 
diff --git a/src/plugins/platforms/windows/qwindowsintegration.h b/src/plugins/platforms/windows/qwindowsintegration.h
index cb10bf08f5..da20d9261a 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.h
+++ b/src/plugins/platforms/windows/qwindowsintegration.h
@@ -60,12 +60,12 @@ public:
     explicit QWindowsIntegration(const QStringList &paramList);
     virtual ~QWindowsIntegration();
 
-    bool hasCapability(QPlatformIntegration::Capability cap) const;
+    bool hasCapability(QPlatformIntegration::Capability cap) const Q_DECL_OVERRIDE;
 
-    QPlatformWindow *createPlatformWindow(QWindow *window) const;
+    QPlatformWindow *createPlatformWindow(QWindow *window) const Q_DECL_OVERRIDE;
 #ifndef QT_NO_OPENGL
     QPlatformOpenGLContext *createPlatformOpenGLContext(QOpenGLContext *context) const Q_DECL_OVERRIDE;
-    QOpenGLContext::OpenGLModuleType openGLModuleType();
+    QOpenGLContext::OpenGLModuleType openGLModuleType() Q_DECL_OVERRIDE;
     static QWindowsStaticOpenGLContext *staticOpenGLContext();
 #endif
     QAbstractEventDispatcher *createEventDispatcher() const Q_DECL_OVERRIDE;
@@ -83,7 +83,7 @@ public:
     QPlatformFontDatabase *fontDatabase() const Q_DECL_OVERRIDE;
     QStringList themeNames() const Q_DECL_OVERRIDE;
     QPlatformTheme *createPlatformTheme(const QString &name) const Q_DECL_OVERRIDE;
-    QPlatformServices *services() const;
+    QPlatformServices *services() const Q_DECL_OVERRIDE;
     QVariant styleHint(StyleHint hint) const Q_DECL_OVERRIDE;
 
     Qt::KeyboardModifiers queryKeyboardModifiers() const Q_DECL_OVERRIDE;
diff --git a/src/plugins/platforms/windows/qwindowsmime.cpp b/src/plugins/platforms/windows/qwindowsmime.cpp
index 0a2ba9b0e7..171ace5c20 100644
--- a/src/plugins/platforms/windows/qwindowsmime.cpp
+++ b/src/plugins/platforms/windows/qwindowsmime.cpp
@@ -897,14 +897,14 @@ public:
     QWindowsMimeHtml();
 
     // for converting from Qt
-    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const;
-    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const;
-    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const;
+    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
+    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const Q_DECL_OVERRIDE;
+    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
 
     // for converting to Qt
-    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const;
-    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const;
-    QString mimeForFormat(const FORMATETC &formatetc) const;
+    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const Q_DECL_OVERRIDE;
+    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const Q_DECL_OVERRIDE;
+    QString mimeForFormat(const FORMATETC &formatetc) const Q_DECL_OVERRIDE;
 
 private:
     int CF_HTML;
@@ -1029,14 +1029,14 @@ class QWindowsMimeImage : public QWindowsMime
 public:
     QWindowsMimeImage();
     // for converting from Qt
-    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const;
-    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const;
-    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const;
+    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
+    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const Q_DECL_OVERRIDE;
+    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
 
     // for converting to Qt
-    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const;
-    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const;
-    QString mimeForFormat(const FORMATETC &formatetc) const;
+    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const Q_DECL_OVERRIDE;
+    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const Q_DECL_OVERRIDE;
+    QString mimeForFormat(const FORMATETC &formatetc) const Q_DECL_OVERRIDE;
 private:
     bool hasOriginalDIBV5(IDataObject *pDataObj) const;
     UINT CF_PNG;
@@ -1183,14 +1183,14 @@ public:
     QBuiltInMimes();
 
     // for converting from Qt
-    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const;
-    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const;
-    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const;
+    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
+    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const Q_DECL_OVERRIDE;
+    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
 
     // for converting to Qt
-    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const;
-    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const;
-    QString mimeForFormat(const FORMATETC &formatetc) const;
+    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const Q_DECL_OVERRIDE;
+    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const Q_DECL_OVERRIDE;
+    QString mimeForFormat(const FORMATETC &formatetc) const Q_DECL_OVERRIDE;
 
 private:
     QMap<int, QString> outFormats;
@@ -1303,14 +1303,14 @@ public:
 
     QLastResortMimes();
     // for converting from Qt
-    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const;
-    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const;
-    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const;
+    bool canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
+    bool convertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData, STGMEDIUM * pmedium) const Q_DECL_OVERRIDE;
+    QVector<FORMATETC> formatsForMime(const QString &mimeType, const QMimeData *mimeData) const Q_DECL_OVERRIDE;
 
     // for converting to Qt
-    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const;
-    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const;
-    QString mimeForFormat(const FORMATETC &formatetc) const;
+    bool canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const Q_DECL_OVERRIDE;
+    QVariant convertToMime(const QString &mime, IDataObject *pDataObj, QVariant::Type preferredType) const Q_DECL_OVERRIDE;
+    QString mimeForFormat(const FORMATETC &formatetc) const Q_DECL_OVERRIDE;
 
 private:
     QMap<int, QString> formats;
diff --git a/src/plugins/platforms/windows/qwindowstheme.h b/src/plugins/platforms/windows/qwindowstheme.h
index b2f8e13b64..fc004b68c8 100644
--- a/src/plugins/platforms/windows/qwindowstheme.h
+++ b/src/plugins/platforms/windows/qwindowstheme.h
@@ -51,9 +51,9 @@ public:
     bool usePlatformNativeDialog(DialogType type) const Q_DECL_OVERRIDE;
     QPlatformDialogHelper *createPlatformDialogHelper(DialogType type) const Q_DECL_OVERRIDE;
     QVariant themeHint(ThemeHint) const Q_DECL_OVERRIDE;
-    virtual const QPalette *palette(Palette type = SystemPalette) const
+    const QPalette *palette(Palette type = SystemPalette) const Q_DECL_OVERRIDE
         { return m_palettes[type]; }
-    virtual const QFont *font(Font type = SystemFont) const
+    const QFont *font(Font type = SystemFont) const Q_DECL_OVERRIDE
         { return m_fonts[type]; }
 
     QPixmap standardPixmap(StandardPixmap sp, const QSizeF &size) const Q_DECL_OVERRIDE;
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index 710cab8597..6fffa1e6e9 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -171,7 +171,7 @@ public:
     void raise() Q_DECL_OVERRIDE;
     void lower() Q_DECL_OVERRIDE;
 
-    void windowEvent(QEvent *event);
+    void windowEvent(QEvent *event) Q_DECL_OVERRIDE;
 
     void propagateSizeHints() Q_DECL_OVERRIDE;
     static bool handleGeometryChangingMessage(MSG *message, const QWindow *qWindow, const QMargins &marginsDp);
@@ -189,8 +189,8 @@ public:
 
     bool startSystemResize(const QPoint &pos, Qt::Corner corner) Q_DECL_OVERRIDE;
 
-    void setFrameStrutEventsEnabled(bool enabled);
-    bool frameStrutEventsEnabled() const { return testFlag(FrameStrutEventsEnabled); }
+    void setFrameStrutEventsEnabled(bool enabled) Q_DECL_OVERRIDE;
+    bool frameStrutEventsEnabled() const Q_DECL_OVERRIDE { return testFlag(FrameStrutEventsEnabled); }
 
     QMargins customMargins() const { return m_data.customMargins; }
     void setCustomMargins(const QMargins &m);
@@ -237,15 +237,15 @@ public:
 
     void setEnabled(bool enabled);
     bool isEnabled() const;
-    void setWindowIcon(const QIcon &icon);
+    void setWindowIcon(const QIcon &icon) Q_DECL_OVERRIDE;
 
     void *surface(void *nativeConfig, int *err);
     void invalidateSurface() Q_DECL_OVERRIDE;
     void aboutToMakeCurrent();
 
 #ifndef Q_OS_WINCE
-    void setAlertState(bool enabled);
-    bool isAlertState() const { return testFlag(AlertState); }
+    void setAlertState(bool enabled) Q_DECL_OVERRIDE;
+    bool isAlertState() const Q_DECL_OVERRIDE { return testFlag(AlertState); }
     void alertWindow(int durationMs = 0);
     void stopAlertWindow();
 #endif