diff --git a/rtengine/curves.h b/rtengine/curves.h
index bc8193b76..1f07e6dbe 100644
--- a/rtengine/curves.h
+++ b/rtengine/curves.h
@@ -454,7 +454,7 @@ public:
     virtual bool   isIdentity () const = 0;
 };
 
-class DiagonalCurve : public Curve
+class DiagonalCurve final : public Curve
 {
 
 protected:
@@ -476,7 +476,7 @@ public:
     };
 };
 
-class FlatCurve : public Curve, public rtengine::NonCopyable
+class FlatCurve final : public Curve, public rtengine::NonCopyable
 {
 
 private:
diff --git a/rtengine/iimage.h b/rtengine/iimage.h
index 7309dd91f..f44c01320 100644
--- a/rtengine/iimage.h
+++ b/rtengine/iimage.h
@@ -658,7 +658,7 @@ public:
 
     /* If any of the required allocation fails, "width" and "height" are set to -1, and all remaining buffer are freed
      * Can be safely used to reallocate an existing image */
-    void allocate (int W, int H) override
+    void allocate (int W, int H) override final
     {
 
         if (W == width && H == height) {
@@ -746,7 +746,7 @@ public:
         }
     }
 
-    void rotate (int deg) override
+    void rotate (int deg) override final
     {
 
         if (deg == 90) {
@@ -873,7 +873,7 @@ public:
         }
     }
 
-    void hflip () override
+    void hflip () override final
     {
         int width2 = width / 2;
 
@@ -905,7 +905,7 @@ public:
 #endif
     }
 
-    void vflip () override
+    void vflip () override final
     {
 
         int height2 = height / 2;
@@ -989,7 +989,7 @@ public:
         }
     }
 
-    void computeHistogramAutoWB (double &avg_r, double &avg_g, double &avg_b, int &n, LUTu &histogram, const int compression) const override
+    void computeHistogramAutoWB (double &avg_r, double &avg_g, double &avg_b, int &n, LUTu &histogram, const int compression) const override final
     {
         histogram.clear();
         avg_r = avg_g = avg_b = 0.;
@@ -1328,7 +1328,7 @@ public:
      * If any of the required allocation fails, "width" and "height" are set to -1, and all remaining buffer are freed
      * Can be safely used to reallocate an existing image or to free up it's memory with "allocate (0,0);"
      */
-    void allocate (int W, int H) override
+    void allocate (int W, int H) override final
     {
 
         if (W == width && H == height) {
@@ -1382,7 +1382,7 @@ public:
         memcpy (dest->data, data, 3 * width * height * sizeof(T));
     }
 
-    void rotate (int deg) override
+    void rotate (int deg) override final
     {
 
         if (deg == 90) {
@@ -1516,7 +1516,7 @@ public:
         }
     }
 
-    void hflip () override
+    void hflip () override final
     {
         int width2 = width / 2;
 
@@ -1552,7 +1552,7 @@ public:
         }
     }
 
-    void vflip () override
+    void vflip () override final
     {
 
         AlignedBuffer<T> lBuffer(3 * width);
@@ -1619,7 +1619,7 @@ public:
         }
     }
 
-    void computeHistogramAutoWB (double &avg_r, double &avg_g, double &avg_b, int &n, LUTu &histogram, const int compression) const override
+    void computeHistogramAutoWB (double &avg_r, double &avg_g, double &avg_b, int &n, LUTu &histogram, const int compression) const override final
     {
         histogram.clear();
         avg_r = avg_g = avg_b = 0.;
diff --git a/rtengine/image16.h b/rtengine/image16.h
index d0053cbfc..de9288f2d 100644
--- a/rtengine/image16.h
+++ b/rtengine/image16.h
@@ -29,7 +29,7 @@ namespace rtengine
 class Image8;
 class Imagefloat;
 
-class Image16 : public IImage16, public ImageIO
+class Image16 final : public IImage16, public ImageIO
 {
 
 public:
diff --git a/rtengine/image8.h b/rtengine/image8.h
index f125dccf8..c11d9d7fc 100644
--- a/rtengine/image8.h
+++ b/rtengine/image8.h
@@ -27,7 +27,7 @@ namespace rtengine
 {
 class Imagefloat;
 
-class Image8 : public IImage8, public ImageIO
+class Image8 final : public IImage8, public ImageIO
 {
 
 public:
diff --git a/rtengine/imagedata.h b/rtengine/imagedata.h
index ff8ed4b86..28d32c5f0 100644
--- a/rtengine/imagedata.h
+++ b/rtengine/imagedata.h
@@ -38,7 +38,7 @@ class TagDirectory;
 namespace rtengine
 {
 
-class FrameData
+class FrameData final
 {
 
 protected:
@@ -95,7 +95,7 @@ public:
     int getRating () const;
 };
 
-class FramesData : public FramesMetaData {
+class FramesData final : public FramesMetaData {
 private:
     // frame's root IFD, can be a file root IFD or a SUB-IFD
     std::vector<std::unique_ptr<FrameData>> frames;
diff --git a/rtengine/imagefloat.h b/rtengine/imagefloat.h
index 4a2b2f7e1..cd08daf70 100644
--- a/rtengine/imagefloat.h
+++ b/rtengine/imagefloat.h
@@ -34,7 +34,7 @@ class LabImage;
 /*
  * Image type used by most tools; expected range: [0.0 ; 65535.0]
  */
-class Imagefloat : public IImagefloat, public ImageIO
+class Imagefloat final : public IImagefloat, public ImageIO
 {
 
 public:
diff --git a/rtengine/imagesource.h b/rtengine/imagesource.h
index e0c26aa9f..d1fa5896e 100644
--- a/rtengine/imagesource.h
+++ b/rtengine/imagesource.h
@@ -143,11 +143,11 @@ public:
 
     virtual void        setProgressListener (ProgressListener* pl) {}
 
-    void        increaseRef () override
+    void        increaseRef () override final
     {
         references++;
     }
-    void        decreaseRef () override
+    void        decreaseRef () override final
     {
         references--;
 
@@ -175,15 +175,15 @@ public:
         return dirpyrdenoiseExpComp;
     }
     // functions inherited from the InitialImage interface
-    Glib::ustring getFileName () override
+    Glib::ustring getFileName () override final
     {
         return fileName;
     }
-    cmsHPROFILE getEmbeddedProfile () override
+    cmsHPROFILE getEmbeddedProfile () override final
     {
         return embProfile;
     }
-    const FramesMetaData* getMetaData () override
+    const FramesMetaData* getMetaData () override final
     {
         return idata;
     }
diff --git a/rtengine/improccoordinator.h b/rtengine/improccoordinator.h
index 96d1f80ce..724443ecd 100644
--- a/rtengine/improccoordinator.h
+++ b/rtengine/improccoordinator.h
@@ -55,7 +55,7 @@ class Crop;
   * but using this class' LUT and other precomputed parameters. The main preview area is displaying a non framed Crop object,
   * while detail windows are framed Crop objects.
   */
-class ImProcCoordinator : public StagedImageProcessor
+class ImProcCoordinator final : public StagedImageProcessor
 {
 
     friend class Crop;
diff --git a/rtengine/processingjob.h b/rtengine/processingjob.h
index 6cdc6bd7c..9c3846958 100644
--- a/rtengine/processingjob.h
+++ b/rtengine/processingjob.h
@@ -24,7 +24,7 @@
 namespace rtengine
 {
 
-class ProcessingJobImpl : public ProcessingJob
+class ProcessingJobImpl final : public ProcessingJob
 {
 
 public:
diff --git a/rtengine/rawimagesource.h b/rtengine/rawimagesource.h
index bd460c61b..6be02f6d6 100644
--- a/rtengine/rawimagesource.h
+++ b/rtengine/rawimagesource.h
@@ -37,7 +37,7 @@ class DiagonalCurve;
 class RetinextransmissionCurve;
 class RetinexgaintransmissionCurve;
 
-class RawImageSource : public ImageSource
+class RawImageSource final : public ImageSource
 {
 private:
     static DiagonalCurve *phaseOneIccCurve;
diff --git a/rtexif/pentaxattribs.cc b/rtexif/pentaxattribs.cc
index 898150696..14f204b08 100644
--- a/rtexif/pentaxattribs.cc
+++ b/rtexif/pentaxattribs.cc
@@ -696,7 +696,7 @@ public:
 };
 PAColorSpaceInterpreter paColorSpaceInterpreter;
 
-class PALensTypeInterpreter : public IntLensInterpreter< int >
+class PALensTypeInterpreter final: public IntLensInterpreter< int >
 {
 public:
     PALensTypeInterpreter ()
diff --git a/rtexif/rtexif.h b/rtexif/rtexif.h
index c37533352..1a956a4a5 100644
--- a/rtexif/rtexif.h
+++ b/rtexif/rtexif.h
@@ -163,14 +163,14 @@ public:
     // Try to get the Tag in the current directory and in subdirectories
     // if lookUpward = true, it will scan the parents TagDirectory up to the root one,
     // but w/o looking into their subdirs
-    virtual Tag*     findTag       (const char* name, bool lookUpward = false) const;
+    Tag*     findTag       (const char* name, bool lookUpward = false) const;
     // Find a all Tags with the given name by scanning the whole tag tree
     std::vector<const Tag*> findTags (const char* name);
     // Find a all Tags with the given ID by scanning the whole tag tree
     std::vector<const Tag*> findTags (int ID);
     // Try to get the Tag in the current directory and in parent directories
     // (won't look into subdirs)
-    virtual Tag*     findTagUpward (const char* name) const;
+    Tag*     findTagUpward (const char* name) const;
     bool             getXMPTagValue (const char* name, char* value) const;
 
     void        keepTag       (int ID);
@@ -191,10 +191,10 @@ public:
     virtual TagDirectory* clone    (TagDirectory* parent) const;
     void     applyChange   (const std::string &field, const Glib::ustring &value);
 
-    virtual void     printAll      (unsigned  int level = 0) const; // reentrant debug function, keep level=0 on first call !
-    virtual bool     CPBDump       (const Glib::ustring &commFName, const Glib::ustring &imageFName, const Glib::ustring &profileFName, const Glib::ustring &defaultPParams,
+    void     printAll      (unsigned  int level = 0) const; // reentrant debug function, keep level=0 on first call !
+    bool     CPBDump       (const Glib::ustring &commFName, const Glib::ustring &imageFName, const Glib::ustring &profileFName, const Glib::ustring &defaultPParams,
                                     const CacheImageData* cfs, const bool flagMode, Glib::KeyFile *keyFile = nullptr, Glib::ustring tagDirName = "") const;
-    virtual void     sort     ();
+    void     sort     ();
 };
 
 // a table of tags: id are offset from beginning and not identifiers
diff --git a/rtexif/sonyminoltaattribs.cc b/rtexif/sonyminoltaattribs.cc
index 4410a4051..82323cede 100644
--- a/rtexif/sonyminoltaattribs.cc
+++ b/rtexif/sonyminoltaattribs.cc
@@ -541,7 +541,7 @@ public:
 };
 SAAntiBlurInterpreter saAntiBlurInterpreter;
 
-class SALensIDInterpreter : public IntLensInterpreter<int>
+class SALensIDInterpreter final : public IntLensInterpreter<int>
 {
 public:
     SALensIDInterpreter ()
@@ -1192,7 +1192,7 @@ public:
 };
 SALensIDInterpreter saLensIDInterpreter;
 
-class SALensID2Interpreter : public IntLensInterpreter< int >
+class SALensID2Interpreter final : public IntLensInterpreter< int >
 {
 public:
     SALensID2Interpreter ()
diff --git a/rtgui/adjuster.h b/rtgui/adjuster.h
index 59250bc81..143268786 100644
--- a/rtgui/adjuster.h
+++ b/rtgui/adjuster.h
@@ -33,7 +33,7 @@ public:
 
 typedef double(*double2double_fun)(double val);
 
-class Adjuster : public Gtk::Grid
+class Adjuster final : public Gtk::Grid
 {
 
 protected:
diff --git a/rtgui/batchqueueentry.h b/rtgui/batchqueueentry.h
index c4cd48615..f06b65046 100644
--- a/rtgui/batchqueueentry.h
+++ b/rtgui/batchqueueentry.h
@@ -50,7 +50,7 @@ struct BatchQueueEntryIdleHelper {
     int pending;
 };
 
-class BatchQueueEntry : public ThumbBrowserEntryBase, public BQEntryUpdateListener, public rtengine::NonCopyable
+class BatchQueueEntry final : public ThumbBrowserEntryBase, public BQEntryUpdateListener, public rtengine::NonCopyable
 {
 
     guint8* opreview;
diff --git a/rtgui/batchtoolpanelcoord.h b/rtgui/batchtoolpanelcoord.h
index 7a5fe77ed..ea11f97c8 100644
--- a/rtgui/batchtoolpanelcoord.h
+++ b/rtgui/batchtoolpanelcoord.h
@@ -28,7 +28,7 @@
 
 class FilePanel;
 class Thumbnail;
-class BatchToolPanelCoordinator :
+class BatchToolPanelCoordinator final :
     public ToolPanelCoordinator,
     public FileSelectionChangeListener,
     public BatchPParamsChangeListener,
diff --git a/rtgui/coloredbar.h b/rtgui/coloredbar.h
index 6cc121cd5..69cfa47d1 100644
--- a/rtgui/coloredbar.h
+++ b/rtgui/coloredbar.h
@@ -30,7 +30,7 @@
  *          the bar itself, i.e. use render_background (depending on its Gtk::Style)
  *
  */
-class ColoredBar : private BackBuffer, public ColorCaller
+class ColoredBar final : private BackBuffer, public ColorCaller
 {
 
 private:
diff --git a/rtgui/coordinateadjuster.h b/rtgui/coordinateadjuster.h
index 70fe42233..24edc707a 100644
--- a/rtgui/coordinateadjuster.h
+++ b/rtgui/coordinateadjuster.h
@@ -69,7 +69,7 @@ public:
  *
  * The position of the Axis in the vector will be used in the communication between the Adjuster and the Provider to identify the Axis
  */
-class CoordinateAdjuster : public Gtk::FlowBox
+class CoordinateAdjuster final : public Gtk::FlowBox
 {
 
 public:
diff --git a/rtgui/cropwindow.h b/rtgui/cropwindow.h
index 491124ad5..623653d2d 100644
--- a/rtgui/cropwindow.h
+++ b/rtgui/cropwindow.h
@@ -54,7 +54,7 @@ public:
 };
 
 class ImageArea;
-class CropWindow : public LWButtonListener, public CropDisplayHandler, public EditCoordSystem, public ObjectMOBuffer, public rtengine::NonCopyable
+class CropWindow final : public LWButtonListener, public CropDisplayHandler, public EditCoordSystem, public ObjectMOBuffer, public rtengine::NonCopyable
 {
     static bool initialized;
 
diff --git a/rtgui/diagonalcurveeditorsubgroup.h b/rtgui/diagonalcurveeditorsubgroup.h
index a077da807..9b1f67462 100644
--- a/rtgui/diagonalcurveeditorsubgroup.h
+++ b/rtgui/diagonalcurveeditorsubgroup.h
@@ -27,7 +27,7 @@
 class DiagonalCurveEditor;
 class MyDiagonalCurve;
 
-class DiagonalCurveEditorSubGroup :
+class DiagonalCurveEditorSubGroup final :
     public CurveEditorSubGroup,
     public SHCListener,
     public AdjusterListener,
diff --git a/rtgui/editcallbacks.h b/rtgui/editcallbacks.h
index c2efcf53e..ee357c2f7 100644
--- a/rtgui/editcallbacks.h
+++ b/rtgui/editcallbacks.h
@@ -129,19 +129,19 @@ public:
     @param picked True if the cursor is still above the the same object than on button pressed and with the same modifier keys.
                   If false, the user moved the cursor away or the modifier key is different, so the element is considered as NOT selected.
     @return true if the preview has to be redrawn, false otherwise */
-    virtual bool pick1 (bool picked);
+    bool pick1 (bool picked);
 
     /** @brief Triggered when the user is releasing mouse button 2 while in action==ES_ACTION_PICKING mode
     @param picked True if the cursor is still above the the same object than on button pressed and with the same modifier keys.
                   If false, the user moved the cursor away or the modifier key is different, so the element is considered as NOT selected.
     @return true if the preview has to be redrawn, false otherwise */
-    virtual bool pick2 (bool picked);
+    bool pick2 (bool picked);
 
     /** @brief Triggered when the user is releasing mouse button 3 while in action==ES_ACTION_PICKING mode
     @param picked True if the cursor is still above the the same object than on button pressed and with the same modifier keys.
                   If false, the user moved the cursor away or the modifier key is different, so the element is considered as NOT selected.
     @return true if the preview has to be redrawn, false otherwise */
-    virtual bool pick3 (bool picked);
+    bool pick3 (bool picked);
 
     /** @brief Get the geometry to be shown to the user */
     const std::vector<Geometry*>& getVisibleGeometry ();
diff --git a/rtgui/exifpanel.h b/rtgui/exifpanel.h
index 0894c21ad..d336d83f9 100644
--- a/rtgui/exifpanel.h
+++ b/rtgui/exifpanel.h
@@ -25,7 +25,7 @@
 #include "toolpanel.h"
 #include "../rtexif/rtexif.h"
 
-class ExifPanel :
+class ExifPanel final :
     public Gtk::VBox,
     public ToolPanel
 {
diff --git a/rtgui/filebrowser.h b/rtgui/filebrowser.h
index 86ab59395..53f3f1f2b 100644
--- a/rtgui/filebrowser.h
+++ b/rtgui/filebrowser.h
@@ -56,7 +56,7 @@ public:
 /*
  * Class handling actions common to all thumbnails of the file browser
  */
-class FileBrowser  : public ThumbBrowserBase,
+class FileBrowser final : public ThumbBrowserBase,
     public LWButtonListener,
     public ExportPanelListener,
     public ProfileStoreListener,
diff --git a/rtgui/filebrowserentry.h b/rtgui/filebrowserentry.h
index ea5140ed6..67b953514 100644
--- a/rtgui/filebrowserentry.h
+++ b/rtgui/filebrowserentry.h
@@ -43,7 +43,7 @@ struct FileBrowserEntryIdleHelper {
 };
 
 class FileThumbnailButtonSet;
-class FileBrowserEntry : public ThumbBrowserEntryBase,
+class FileBrowserEntry final : public ThumbBrowserEntryBase,
     public ThumbnailListener,
     public ThumbImageUpdateListener,
     public rtengine::NonCopyable
diff --git a/rtgui/filecatalog.h b/rtgui/filecatalog.h
index 8f7e5618f..b94d049d0 100644
--- a/rtgui/filecatalog.h
+++ b/rtgui/filecatalog.h
@@ -43,7 +43,7 @@ class ToolBar;
  *   - handling the thumbnail toolbar,
  *   - monitoring the directory (for any change)
  */
-class FileCatalog : public Gtk::VBox,
+class FileCatalog final : public Gtk::VBox,
     public PreviewLoaderListener,
     public FilterPanelListener,
     public FileBrowserListener,
diff --git a/rtgui/flatcurveeditorsubgroup.h b/rtgui/flatcurveeditorsubgroup.h
index c358dde3b..865a0ef83 100644
--- a/rtgui/flatcurveeditorsubgroup.h
+++ b/rtgui/flatcurveeditorsubgroup.h
@@ -27,7 +27,7 @@
 class FlatCurveEditor;
 class MyFlatCurve;
 
-class FlatCurveEditorSubGroup:
+class FlatCurveEditorSubGroup final :
     public CurveEditorSubGroup,
     public rtengine::NonCopyable
 {
diff --git a/rtgui/guiutils.h b/rtgui/guiutils.h
index 97c72513b..d4c91734a 100644
--- a/rtgui/guiutils.h
+++ b/rtgui/guiutils.h
@@ -92,7 +92,7 @@ private:
  *     }
  *   </code>
  */
-class GThreadLock
+class GThreadLock final
 {
 public:
     GThreadLock()
@@ -110,7 +110,7 @@ public:
  *
  * Will relock on destruction.
  */
-class GThreadUnLock
+class GThreadUnLock final
 {
 public:
     GThreadUnLock()
@@ -125,7 +125,7 @@ public:
 
 #pragma GCC diagnostic pop
 
-class ConnectionBlocker
+class ConnectionBlocker final
 {
 public:
     explicit ConnectionBlocker (Gtk::Widget *associatedWidget, sigc::connection& connection) : connection (associatedWidget ? &connection : nullptr), wasBlocked(false)
@@ -152,7 +152,7 @@ private:
 /**
  * @brief Glue box to control visibility of the MyExpender's content ; also handle the frame around it
  */
-class ExpanderBox: public Gtk::EventBox
+class ExpanderBox final : public Gtk::EventBox
 {
 private:
     Gtk::Container *pC;
@@ -185,7 +185,7 @@ public:
  *
  * Warning: once you've instantiated this class with a text label or a widget label, you won't be able to revert to the other solution.
  */
-class MyExpander : public Gtk::VBox
+class MyExpander final : public Gtk::VBox
 {
 public:
     typedef sigc::signal<void> type_signal_enabled_toggled;
@@ -295,7 +295,7 @@ public:
 /**
  * @brief subclass of Gtk::ScrolledWindow in order to handle the scrollwheel
  */
-class MyScrolledWindow : public Gtk::ScrolledWindow
+class MyScrolledWindow final : public Gtk::ScrolledWindow
 {
 
     bool on_scroll_event (GdkEventScroll* event) override;
@@ -310,7 +310,7 @@ public:
 /**
  * @brief subclass of Gtk::ScrolledWindow in order to handle the large toolbars (wider than available space)
  */
-class MyScrolledToolbar : public Gtk::ScrolledWindow
+class MyScrolledToolbar final : public Gtk::ScrolledWindow
 {
 
     bool on_scroll_event (GdkEventScroll* event) override;
@@ -340,7 +340,7 @@ public:
 /**
  * @brief subclass of Gtk::ComboBoxText in order to handle the scrollwheel
  */
-class MyComboBoxText : public Gtk::ComboBoxText
+class MyComboBoxText final : public Gtk::ComboBoxText
 {
     int naturalWidth, minimumWidth;
     sigc::connection myConnection;
@@ -360,7 +360,7 @@ public:
 /**
  * @brief subclass of Gtk::SpinButton in order to handle the scrollwheel
  */
-class MySpinButton : public Gtk::SpinButton
+class MySpinButton final : public Gtk::SpinButton
 {
 
 protected:
@@ -375,7 +375,7 @@ public:
 /**
  * @brief subclass of Gtk::HScale in order to handle the scrollwheel
  */
-class MyHScale : public Gtk::HScale
+class MyHScale final : public Gtk::HScale
 {
 
     bool on_scroll_event (GdkEventScroll* event) override;
@@ -385,7 +385,7 @@ class MyHScale : public Gtk::HScale
 /**
  * @brief subclass of Gtk::FileChooserButton in order to handle the scrollwheel
  */
-class MyFileChooserButton: public Gtk::Button {
+class MyFileChooserButton final : public Gtk::Button {
 private:
     void show_chooser();
 
@@ -473,14 +473,14 @@ typedef enum RTNav {
 /**
  * @brief Handle the switch between text and image to be displayed in the HBox (to be used in a button/toolpanel)
  */
-class TextOrIcon : public Gtk::HBox
+class TextOrIcon final : public Gtk::HBox
 {
 
 public:
     TextOrIcon (const Glib::ustring &filename, const Glib::ustring &labelTx, const Glib::ustring &tooltipTx);
 };
 
-class MyImageMenuItem : public Gtk::MenuItem
+class MyImageMenuItem final : public Gtk::MenuItem
 {
 private:
     Gtk::Grid *box;
@@ -493,7 +493,7 @@ public:
     const Gtk::Label* getLabel () const;
 };
 
-class MyProgressBar : public Gtk::ProgressBar
+class MyProgressBar final : public Gtk::ProgressBar
 {
 private:
     int w;
@@ -512,7 +512,7 @@ public:
 /**
  * @brief Define a gradient milestone
  */
-class GradientMilestone
+class GradientMilestone final
 {
 public:
     double position;
diff --git a/rtgui/histogrampanel.h b/rtgui/histogrampanel.h
index 4fd21bcc2..cec44ed03 100644
--- a/rtgui/histogrampanel.h
+++ b/rtgui/histogrampanel.h
@@ -53,7 +53,7 @@ public:
     double log (double vsize, double val);
 };
 
-class HistogramRGBArea : public Gtk::DrawingArea, public BackBuffer, private HistogramScaling, public rtengine::NonCopyable
+class HistogramRGBArea final : public Gtk::DrawingArea, public BackBuffer, private HistogramScaling, public rtengine::NonCopyable
 {
 private:
     typedef const double (*TMatrix)[3];
@@ -116,7 +116,7 @@ public:
     virtual void toggleButtonMode() = 0;
 };
 
-class HistogramArea : public Gtk::DrawingArea, public BackBuffer, private HistogramScaling, public rtengine::NonCopyable
+class HistogramArea final : public Gtk::DrawingArea, public BackBuffer, private HistogramScaling, public rtengine::NonCopyable
 {
 public:
     typedef sigc::signal<void, double> type_signal_factor_changed;
@@ -174,7 +174,7 @@ private:
     void get_preferred_width_for_height_vfunc (int height, int &minimum_width, int &natural_width) const override;
 };
 
-class HistogramPanel : public Gtk::Grid, public PointerMotionListener, public DrawModeListener, public rtengine::NonCopyable
+class HistogramPanel final : public Gtk::Grid, public PointerMotionListener, public DrawModeListener, public rtengine::NonCopyable
 {
 
 protected:
diff --git a/rtgui/iccprofilecreator.h b/rtgui/iccprofilecreator.h
index 2cd19e14f..8ee46a71d 100644
--- a/rtgui/iccprofilecreator.h
+++ b/rtgui/iccprofilecreator.h
@@ -27,7 +27,7 @@
 
 class RTWindow;
 
-class ICCProfileCreator : public Gtk::Dialog, public AdjusterListener
+class ICCProfileCreator final : public Gtk::Dialog, public AdjusterListener
 {
 
 private:
diff --git a/rtgui/imagearea.h b/rtgui/imagearea.h
index 28b52dcd2..586bba7a7 100644
--- a/rtgui/imagearea.h
+++ b/rtgui/imagearea.h
@@ -34,7 +34,7 @@
 
 class ImageAreaPanel;
 
-class ImageArea :
+class ImageArea final :
     public Gtk::DrawingArea,
     public CropWindowListener,
     public EditDataProvider,
diff --git a/rtgui/imageareapanel.h b/rtgui/imageareapanel.h
index 831371dbb..f52ca9060 100644
--- a/rtgui/imageareapanel.h
+++ b/rtgui/imageareapanel.h
@@ -22,7 +22,7 @@
 
 class ImageArea;
 
-class ImageAreaPanel :
+class ImageAreaPanel final :
     public Gtk::VBox
 {
 
diff --git a/rtgui/inspector.h b/rtgui/inspector.h
index 8338259bf..1526f90be 100644
--- a/rtgui/inspector.h
+++ b/rtgui/inspector.h
@@ -40,7 +40,7 @@ public:
     //~InspectorBuffer();
 };
 
-class Inspector : public Gtk::DrawingArea
+class Inspector final : public Gtk::DrawingArea
 {
 
 private:
diff --git a/rtgui/iptcpanel.h b/rtgui/iptcpanel.h
index 15d117f87..100904d1a 100644
--- a/rtgui/iptcpanel.h
+++ b/rtgui/iptcpanel.h
@@ -25,7 +25,7 @@
 #include "guiutils.h"
 #include "toolpanel.h"
 
-class IPTCPanel :
+class IPTCPanel final :
     public Gtk::VBox,
     public ToolPanel
 {
diff --git a/rtgui/lockablecolorpicker.h b/rtgui/lockablecolorpicker.h
index 77d2e8e9f..baeea41ef 100644
--- a/rtgui/lockablecolorpicker.h
+++ b/rtgui/lockablecolorpicker.h
@@ -33,7 +33,7 @@ public:
     virtual void switchPickerVisibility(bool isVisible) = 0;
 };
 
-class LockableColorPicker : BackBuffer
+class LockableColorPicker final : BackBuffer
 {
 public:
     enum class Size {
diff --git a/rtgui/mydiagonalcurve.h b/rtgui/mydiagonalcurve.h
index b38373006..b2b83c02e 100644
--- a/rtgui/mydiagonalcurve.h
+++ b/rtgui/mydiagonalcurve.h
@@ -41,7 +41,7 @@ public:
     std::vector<double> x, y;   // in case of parametric curves the curve parameters are stored in vector x. In other cases these vectors store the coordinates of the bullets.
 };
 
-class MyDiagonalCurve : public MyCurve
+class MyDiagonalCurve final : public MyCurve
 {
 private:
     IdleRegister idle_register;
diff --git a/rtgui/myflatcurve.h b/rtgui/myflatcurve.h
index 88d651a05..5da1d09ad 100644
--- a/rtgui/myflatcurve.h
+++ b/rtgui/myflatcurve.h
@@ -66,7 +66,7 @@ public:
     double centerY;
 };
 
-class MyFlatCurve : public MyCurve
+class MyFlatCurve final : public MyCurve
 {
 
 protected:
diff --git a/rtgui/navigator.h b/rtgui/navigator.h
index c1c23c6dc..e9d40e309 100644
--- a/rtgui/navigator.h
+++ b/rtgui/navigator.h
@@ -25,7 +25,7 @@
 
 class PreviewWindow;
 
-class Navigator :
+class Navigator final :
     public Gtk::Frame,
     public PointerMotionListener
 {
diff --git a/rtgui/partialpastedlg.h b/rtgui/partialpastedlg.h
index 1403e7c1b..75e18e83c 100644
--- a/rtgui/partialpastedlg.h
+++ b/rtgui/partialpastedlg.h
@@ -34,7 +34,7 @@ class ProcParams;
 
 struct ParamsEdited;
 
-class PartialPasteDlg : public Gtk::Dialog
+class PartialPasteDlg final : public Gtk::Dialog
 {
 
 public:
diff --git a/rtgui/popupbutton.h b/rtgui/popupbutton.h
index 87b1b73a6..a67339a9f 100644
--- a/rtgui/popupbutton.h
+++ b/rtgui/popupbutton.h
@@ -24,7 +24,7 @@
 
 #include "popupcommon.h"
 
-class PopUpButton :
+class PopUpButton final :
     public Gtk::Button,
     public PopUpCommon
 {
diff --git a/rtgui/preferences.h b/rtgui/preferences.h
index 76a104ffa..a6cbe7939 100644
--- a/rtgui/preferences.h
+++ b/rtgui/preferences.h
@@ -29,7 +29,7 @@
 class RTWindow;
 class Splash;
 
-class Preferences :
+class Preferences final :
     public Gtk::Dialog,
     public ProfileStoreListener
 {
diff --git a/rtgui/previewhandler.h b/rtgui/previewhandler.h
index d9c91f6ad..4fd9a1e82 100644
--- a/rtgui/previewhandler.h
+++ b/rtgui/previewhandler.h
@@ -44,7 +44,7 @@ struct PreviewHandlerIdleHelper {
     int pending;
 };
 
-class PreviewHandler : public rtengine::PreviewImageListener, public rtengine::NonCopyable
+class PreviewHandler final : public rtengine::PreviewImageListener, public rtengine::NonCopyable
 {
 private:
     friend int setImageUI   (void* data);
diff --git a/rtgui/profilepanel.h b/rtgui/profilepanel.h
index b3c968682..c3a125c49 100644
--- a/rtgui/profilepanel.h
+++ b/rtgui/profilepanel.h
@@ -49,7 +49,7 @@ class PartialProfile;
 }
 class RTImage;
 
-class ProfilePanel :
+class ProfilePanel final :
     public Gtk::Grid,
     public PParamsChangeListener,
     public ProfileStoreListener,
diff --git a/rtgui/progressconnector.h b/rtgui/progressconnector.h
index f4d1d8f7e..90c9f67f0 100644
--- a/rtgui/progressconnector.h
+++ b/rtgui/progressconnector.h
@@ -28,7 +28,7 @@
 
 #undef THREAD_PRIORITY_NORMAL
 
-class PLDBridge :
+class PLDBridge final :
     public rtengine::ProgressListener
 {
 public:
diff --git a/rtgui/renamedlg.h b/rtgui/renamedlg.h
index f9447fbac..3c92965f8 100644
--- a/rtgui/renamedlg.h
+++ b/rtgui/renamedlg.h
@@ -26,7 +26,7 @@
 
 class CacheImageData;
 
-class RenameDialog :
+class RenameDialog final :
     public Gtk::Dialog
 {
 
diff --git a/rtgui/rtimage.h b/rtgui/rtimage.h
index b68becd82..eb1930d28 100644
--- a/rtgui/rtimage.h
+++ b/rtgui/rtimage.h
@@ -25,7 +25,7 @@
 /**
  * @brief A derived class of Gtk::Image in order to handle theme-related icon sets.
  */
-class RTImage : public Gtk::Image, public RTScalable
+class RTImage final : public Gtk::Image, public RTScalable
 {
     static double dpiBack; // used to keep track of master dpi change
     static int scaleBack;  // used to keep track of master scale change
diff --git a/rtgui/rtwindow.h b/rtgui/rtwindow.h
index 4791ac6c1..c493c2db4 100644
--- a/rtgui/rtwindow.h
+++ b/rtgui/rtwindow.h
@@ -35,7 +35,7 @@ class BatchQueuePanel;
 class EditorPanel;
 class FilePanel;
 class PLDBridge;
-class RTWindow :
+class RTWindow final :
     public Gtk::Window,
     public rtengine::ProgressListener,
     public rtengine::NonCopyable
diff --git a/rtgui/saveasdlg.h b/rtgui/saveasdlg.h
index 448b37fd7..445452a54 100644
--- a/rtgui/saveasdlg.h
+++ b/rtgui/saveasdlg.h
@@ -22,7 +22,7 @@
 
 #include "saveformatpanel.h"
 
-class SaveAsDialog :
+class SaveAsDialog final :
     public Gtk::Dialog,
     public FormatChangeListener
 {
diff --git a/rtgui/shcselector.h b/rtgui/shcselector.h
index 5c4421e0a..e03ca8e06 100644
--- a/rtgui/shcselector.h
+++ b/rtgui/shcselector.h
@@ -29,7 +29,7 @@ public:
     virtual void shcChanged() = 0;
 };
 
-class SHCSelector : public Gtk::DrawingArea, BackBuffer
+class SHCSelector final : public Gtk::DrawingArea, BackBuffer
 {
 
 protected:
diff --git a/rtgui/splash.h b/rtgui/splash.h
index 363c51489..bc63cef91 100644
--- a/rtgui/splash.h
+++ b/rtgui/splash.h
@@ -20,7 +20,7 @@
 
 #include <gtkmm.h>
 
-class SplashImage :
+class SplashImage final :
     public Gtk::DrawingArea
 {
 
@@ -39,7 +39,7 @@ public:
 };
 
 //class Splash : public Gtk::Window {
-class Splash : public Gtk::Dialog
+class Splash final : public Gtk::Dialog
 {
 
 private:
diff --git a/rtgui/thresholdselector.h b/rtgui/thresholdselector.h
index f948b56ad..886b82fbd 100644
--- a/rtgui/thresholdselector.h
+++ b/rtgui/thresholdselector.h
@@ -113,10 +113,10 @@ protected:
     void updateBackBuffer();
 
     Gtk::SizeRequestMode get_request_mode_vfunc () const override;
-    void get_preferred_height_vfunc (int& minimum_height, int& natural_height) const override;
-    void get_preferred_width_vfunc (int &minimum_width, int &natural_width) const override;
-    void get_preferred_height_for_width_vfunc (int width, int &minimum_height, int &natural_height) const override;
-    void get_preferred_width_for_height_vfunc (int height, int &minimum_width, int &natural_width) const override;
+    void get_preferred_height_vfunc (int& minimum_height, int& natural_height) const override final;
+    void get_preferred_width_vfunc (int &minimum_width, int &natural_width) const override final;
+    void get_preferred_height_for_width_vfunc (int width, int &minimum_height, int &natural_height) const override final;
+    void get_preferred_width_for_height_vfunc (int height, int &minimum_width, int &natural_width) const override final;
     void on_realize () override;
     bool on_draw(const ::Cairo::RefPtr< Cairo::Context> &cr) override;
     bool on_button_press_event (GdkEventButton* event) override;
diff --git a/rtgui/thumbbrowserbase.h b/rtgui/thumbbrowserbase.h
index b4caac0a9..e1f24594c 100644
--- a/rtgui/thumbbrowserbase.h
+++ b/rtgui/thumbbrowserbase.h
@@ -60,10 +60,10 @@ class ThumbBrowserBase :
         bool on_draw(const ::Cairo::RefPtr< Cairo::Context> &cr) override;
 
         Gtk::SizeRequestMode get_request_mode_vfunc () const override;
-        void get_preferred_height_vfunc (int &minimum_height, int &natural_height) const override;
-        void get_preferred_width_vfunc (int &minimum_width, int &natural_width) const override;
-        void get_preferred_height_for_width_vfunc (int width, int &minimum_height, int &natural_height) const override;
-        void get_preferred_width_for_height_vfunc (int height, int &minimum_width, int &natural_width) const override;
+        void get_preferred_height_vfunc (int &minimum_height, int &natural_height) const override final;
+        void get_preferred_width_vfunc (int &minimum_width, int &natural_width) const override final;
+        void get_preferred_height_for_width_vfunc (int width, int &minimum_height, int &natural_height) const override final;
+        void get_preferred_width_for_height_vfunc (int height, int &minimum_width, int &natural_width) const override final;
 
         bool on_button_press_event (GdkEventButton* event) override;
         bool on_button_release_event (GdkEventButton* event) override;
diff --git a/rtgui/toolpanel.h b/rtgui/toolpanel.h
index aecf1f39f..069654128 100644
--- a/rtgui/toolpanel.h
+++ b/rtgui/toolpanel.h
@@ -143,7 +143,7 @@ public:
         this->batchMode = batchMode;
     }
 
-    virtual Glib::ustring getToolName () {
+    Glib::ustring getToolName () {
         return toolName;
     }
 };
@@ -164,11 +164,11 @@ public:
 
     FoldableToolPanel(Gtk::Box* content, Glib::ustring toolName, Glib::ustring UILabel, bool need11 = false, bool useEnabled = false);
 
-    MyExpander* getExpander() override
+    MyExpander* getExpander() override final
     {
         return exp;
     }
-    void setExpanded (bool expanded) override
+    void setExpanded (bool expanded) override final
     {
         if (exp) {
             exp->set_expanded( expanded );
@@ -186,7 +186,7 @@ public:
             exp->show();
         }
     }
-    bool getExpanded () override
+    bool getExpanded () override final
     {
         if (exp) {
             return exp->get_expanded();
@@ -194,11 +194,11 @@ public:
 
         return false;
     }
-    void setParent (Gtk::Box* parent) override
+    void setParent (Gtk::Box* parent) override final
     {
         parentContainer = parent;
     }
-    Gtk::Box* getParent () override
+    Gtk::Box* getParent () override final
     {
         return parentContainer;
     }
diff --git a/rtgui/toolpanelcoord.h b/rtgui/toolpanelcoord.h
index 4313f6d12..17f14673d 100644
--- a/rtgui/toolpanelcoord.h
+++ b/rtgui/toolpanelcoord.h
@@ -318,7 +318,7 @@ public:
     int getSpotWBRectSize() const override;
     void cropSelectionReady() override;
     void rotateSelectionReady(double rotate_deg, Thumbnail* thm = nullptr) override;
-    ToolBar* getToolBar() const override;
+    ToolBar* getToolBar() const override final;
     CropGUIListener* startCropEditing(Thumbnail* thm = nullptr) override;
 
     void updateTPVScrollbar (bool hide);
@@ -326,7 +326,7 @@ public:
 
     // ToolBarListener interface
     void toolSelected (ToolMode tool) override;
-    void editModeSwitchedOff () override;
+    void editModeSwitchedOff () override final;
 
     void setEditProvider (EditDataProvider *provider);