diff --git a/src/platform/guigtk.cpp b/src/platform/guigtk.cpp
index cf0c137..7d06ddf 100644
--- a/src/platform/guigtk.cpp
+++ b/src/platform/guigtk.cpp
@@ -63,7 +63,7 @@ void FatalError(std::string message) {
 // Settings
 //-----------------------------------------------------------------------------
 
-class SettingsImplGtk : public Settings {
+class SettingsImplGtk final : public Settings {
 public:
     // Why aren't we using GSettings? Two reasons. It doesn't allow to easily see whether
     // the setting had the default value, and it requires to install a schema globally.
@@ -198,7 +198,7 @@ SettingsRef GetSettings() {
 // Timers
 //-----------------------------------------------------------------------------
 
-class TimerImplGtk : public Timer {
+class TimerImplGtk final : public Timer {
 public:
     sigc::connection    _connection;
 
@@ -276,7 +276,7 @@ protected:
 // Menus
 //-----------------------------------------------------------------------------
 
-class MenuItemImplGtk : public MenuItem {
+class MenuItemImplGtk final : public MenuItem {
 public:
     GtkMenuItem gtkMenuItem;
 
@@ -338,7 +338,7 @@ public:
     }
 };
 
-class MenuImplGtk : public Menu {
+class MenuImplGtk final : public Menu {
 public:
     Gtk::Menu   gtkMenu;
     std::vector<std::shared_ptr<MenuItemImplGtk>>   menuItems;
@@ -401,7 +401,7 @@ MenuRef CreateMenu() {
     return std::make_shared<MenuImplGtk>();
 }
 
-class MenuBarImplGtk : public MenuBar {
+class MenuBarImplGtk final : public MenuBar {
 public:
     Gtk::MenuBar    gtkMenuBar;
     std::vector<std::shared_ptr<MenuImplGtk>>       subMenus;
@@ -805,7 +805,7 @@ protected:
 // Windows
 //-----------------------------------------------------------------------------
 
-class WindowImplGtk : public Window {
+class WindowImplGtk final : public Window {
 public:
     GtkWindow       gtkWindow;
     MenuBarRef      menuBar;
@@ -1069,7 +1069,7 @@ void Request3DConnexionEventsForWindow(WindowRef window) {}
 // Message dialogs
 //-----------------------------------------------------------------------------
 
-class MessageDialogImplGtk : public MessageDialog {
+class MessageDialogImplGtk final : public MessageDialog {
 public:
     Gtk::Image         gtkImage;
     Gtk::MessageDialog gtkDialog;
@@ -1156,7 +1156,7 @@ MessageDialogRef CreateMessageDialog(WindowRef parentWindow) {
 // File dialogs
 //-----------------------------------------------------------------------------
 
-class FileDialogImplGtk : public FileDialog {
+class FileDialogImplGtk final : public FileDialog {
 public:
     Gtk::FileChooserDialog      gtkDialog;
     std::vector<std::string>    extensions;
diff --git a/src/platform/guimac.mm b/src/platform/guimac.mm
index 472087f..59c10be 100644
--- a/src/platform/guimac.mm
+++ b/src/platform/guimac.mm
@@ -93,7 +93,7 @@ void FatalError(std::string message) {
 // Settings
 //-----------------------------------------------------------------------------
 
-class SettingsImplCocoa : public Settings {
+class SettingsImplCocoa final : public Settings {
 public:
     NSUserDefaults *userDefaults;
 
@@ -159,7 +159,7 @@ SettingsRef GetSettings() {
 // Timers
 //-----------------------------------------------------------------------------
 
-class TimerImplCocoa : public Timer {
+class TimerImplCocoa final : public Timer {
 public:
     NSTimer *timer;
 
@@ -194,7 +194,7 @@ TimerRef CreateTimer() {
 // Menus
 //-----------------------------------------------------------------------------
 
-class MenuItemImplCocoa : public MenuItem {
+class MenuItemImplCocoa final : public MenuItem {
 public:
     SSFunction *ssFunction;
     NSMenuItem *nsMenuItem;
@@ -244,7 +244,7 @@ public:
     }
 };
 
-class MenuImplCocoa : public Menu {
+class MenuImplCocoa final : public Menu {
 public:
     NSMenu *nsMenu;
 
@@ -298,7 +298,7 @@ MenuRef CreateMenu() {
     return std::make_shared<MenuImplCocoa>();
 }
 
-class MenuBarImplCocoa : public MenuBar {
+class MenuBarImplCocoa final : public MenuBar {
 public:
     NSMenu *nsMenuBar;
 
@@ -756,7 +756,7 @@ namespace Platform {
 // Windows
 //-----------------------------------------------------------------------------
 
-class WindowImplCocoa : public Window {
+class WindowImplCocoa final : public Window {
 public:
     NSWindow         *nsWindow;
     SSWindowDelegate *ssWindowDelegate;
@@ -1159,7 +1159,7 @@ void Request3DConnexionEventsForWindow(WindowRef window) {
 // Message dialogs
 //-----------------------------------------------------------------------------
 
-class MessageDialogImplCocoa : public MessageDialog {
+class MessageDialogImplCocoa final : public MessageDialog {
 public:
     NSAlert  *nsAlert  = [[NSAlert alloc] init];
     NSWindow *nsWindow;
@@ -1294,7 +1294,7 @@ public:
     }
 };
 
-class OpenFileDialogImplCocoa : public FileDialogImplCocoa {
+class OpenFileDialogImplCocoa final : public FileDialogImplCocoa {
 public:
     NSMutableArray *nsFilter = [[NSMutableArray alloc] init];
 
@@ -1310,7 +1310,7 @@ public:
     }
 };
 
-class SaveFileDialogImplCocoa : public FileDialogImplCocoa {
+class SaveFileDialogImplCocoa final : public FileDialogImplCocoa {
 public:
     NSMutableArray         *nsFilters   = [[NSMutableArray alloc] init];
     SSSaveFormatAccessory  *ssAccessory = nil;
diff --git a/src/platform/guinone.cpp b/src/platform/guinone.cpp
index 0307745..eada384 100644
--- a/src/platform/guinone.cpp
+++ b/src/platform/guinone.cpp
@@ -51,7 +51,7 @@ void FatalError(std::string message) {
 // Settings
 //-----------------------------------------------------------------------------
 
-class SettingsImplDummy : public Settings {
+class SettingsImplDummy final : public Settings {
 public:
     void FreezeInt(const std::string &key, uint32_t value) {}
 
@@ -83,7 +83,7 @@ SettingsRef GetSettings() {
 // Timers
 //-----------------------------------------------------------------------------
 
-class TimerImplDummy : public Timer {
+class TimerImplDummy final : public Timer {
 public:
     void RunAfter(unsigned milliseconds) override {}
 };
diff --git a/src/platform/guiwin.cpp b/src/platform/guiwin.cpp
index fa64175..0da75a8 100644
--- a/src/platform/guiwin.cpp
+++ b/src/platform/guiwin.cpp
@@ -143,7 +143,7 @@ void FatalError(std::string message) {
 // Settings
 //-----------------------------------------------------------------------------
 
-class SettingsImplWin32 : public Settings {
+class SettingsImplWin32 final : public Settings {
 public:
     HKEY hKey = NULL;
 
@@ -224,7 +224,7 @@ SettingsRef GetSettings() {
 // Timers
 //-----------------------------------------------------------------------------
 
-class TimerImplWin32 : public Timer {
+class TimerImplWin32 final : public Timer {
 public:
     static HWND WindowHandle() {
         static HWND hTimerWnd;
@@ -267,7 +267,7 @@ TimerRef CreateTimer() {
 
 class MenuImplWin32;
 
-class MenuItemImplWin32 : public MenuItem {
+class MenuItemImplWin32 final : public MenuItem {
 public:
     std::shared_ptr<MenuImplWin32> menu;
 
@@ -340,7 +340,7 @@ public:
 
 int64_t contextMenuPopTime = 0;
 
-class MenuImplWin32 : public Menu {
+class MenuImplWin32 final : public Menu {
 public:
     HMENU hMenu;
 
@@ -426,7 +426,7 @@ MenuRef CreateMenu() {
     return menu;
 }
 
-class MenuBarImplWin32 : public MenuBar {
+class MenuBarImplWin32 final : public MenuBar {
 public:
     HMENU hMenuBar;
 
@@ -471,7 +471,7 @@ MenuBarRef GetOrCreateMainMenu(bool *unique) {
 
 #define SCROLLBAR_UNIT 65536
 
-class WindowImplWin32 : public Window {
+class WindowImplWin32 final : public Window {
 public:
     HWND hWindow  = NULL;
     HWND hTooltip = NULL;
@@ -1357,7 +1357,7 @@ void Request3DConnexionEventsForWindow(WindowRef window) {}
 // Message dialogs
 //-----------------------------------------------------------------------------
 
-class MessageDialogImplWin32 : public MessageDialog {
+class MessageDialogImplWin32 final : public MessageDialog {
 public:
     MSGBOXPARAMSW       mbp = {};
 
@@ -1467,7 +1467,7 @@ MessageDialogRef CreateMessageDialog(WindowRef parentWindow) {
 // File dialogs
 //-----------------------------------------------------------------------------
 
-class FileDialogImplWin32 : public FileDialog {
+class FileDialogImplWin32 final : public FileDialog {
 public:
     OPENFILENAMEW   ofn = {};
     bool            isSaveDialog;
diff --git a/src/render/rendergl1.cpp b/src/render/rendergl1.cpp
index d06a739..de48644 100644
--- a/src/render/rendergl1.cpp
+++ b/src/render/rendergl1.cpp
@@ -166,7 +166,7 @@ static void ssglFillPattern(Canvas::FillPattern pattern) {
 // OpenGL 1 / compatibility profile based renderer
 //-----------------------------------------------------------------------------
 
-class OpenGl1Renderer : public ViewportCanvas {
+class OpenGl1Renderer final : public ViewportCanvas {
 public:
     Camera      camera;
     Lighting    lighting;
diff --git a/src/render/rendergl3.cpp b/src/render/rendergl3.cpp
index c53a72d..827a467 100644
--- a/src/render/rendergl3.cpp
+++ b/src/render/rendergl3.cpp
@@ -40,7 +40,7 @@ public:
 };
 
 // A canvas that uses the core OpenGL 3 profile, for desktop systems.
-class OpenGl2Renderer : public ViewportCanvas {
+class OpenGl2Renderer final : public ViewportCanvas {
 public:
     struct SEdgeListItem {
         hStroke         h;
@@ -716,7 +716,7 @@ public:
     virtual void Remove(OpenGl2Renderer *renderer) = 0;
 };
 
-class EdgeDrawCall : public DrawCall {
+class EdgeDrawCall final : public DrawCall {
 public:
     // Key
     Canvas::Stroke              stroke;
@@ -745,7 +745,7 @@ public:
     }
 };
 
-class OutlineDrawCall : public DrawCall {
+class OutlineDrawCall final : public DrawCall {
 public:
     // Key
     Canvas::Stroke              stroke;
@@ -777,7 +777,7 @@ public:
     }
 };
 
-class PointDrawCall : public DrawCall {
+class PointDrawCall final : public DrawCall {
 public:
     // Key
     Canvas::Stroke               stroke;
@@ -806,7 +806,7 @@ public:
     }
 };
 
-class PixmapDrawCall : public DrawCall {
+class PixmapDrawCall final : public DrawCall {
 public:
     // Key
     Canvas::Fill                 fill;
@@ -842,7 +842,7 @@ public:
     }
 };
 
-class MeshDrawCall : public DrawCall {
+class MeshDrawCall final : public DrawCall {
 public:
     // Key
     Canvas::Fill            fillFront;
@@ -903,7 +903,7 @@ public:
 };
 
 struct CompareDrawCall {
-    bool operator()(const std::shared_ptr<DrawCall> &a, const std::shared_ptr<DrawCall> &b) {
+    bool operator()(const std::shared_ptr<DrawCall> &a, const std::shared_ptr<DrawCall> &b) const {
         const Canvas::Layer stackup[] = {
             Canvas::Layer::BACK,
             Canvas::Layer::DEPTH_ONLY,
@@ -924,7 +924,7 @@ struct CompareDrawCall {
     }
 };
 
-class OpenGl2RendererBatch : public BatchCanvas {
+class OpenGl2RendererBatch final : public BatchCanvas {
 public:
     struct EdgeBuffer {
         hStroke         h;