diff --git a/intern/ghost/intern/GHOST_ContextEGL.h b/intern/ghost/intern/GHOST_ContextEGL.h
index 3ccd34f0338..5bfa540f474 100644
--- a/intern/ghost/intern/GHOST_ContextEGL.h
+++ b/intern/ghost/intern/GHOST_ContextEGL.h
@@ -43,52 +43,52 @@ class GHOST_ContextEGL : public GHOST_Context {
   /**
    * Destructor.
    */
-  ~GHOST_ContextEGL();
+  ~GHOST_ContextEGL() override;
 
   /**
    * Swaps front and back buffers of a window.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess swapBuffers();
+  GHOST_TSuccess swapBuffers() override;
 
   /**
    * Activates the drawing context of this window.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess activateDrawingContext();
+  GHOST_TSuccess activateDrawingContext() override;
 
   /**
    * Release the drawing context of the calling thread.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess releaseDrawingContext();
+  GHOST_TSuccess releaseDrawingContext() override;
 
   /**
    * Call immediately after new to initialize.  If this fails then immediately delete the object.
    * \return Indication as to whether initialization has succeeded.
    */
-  GHOST_TSuccess initializeDrawingContext();
+  GHOST_TSuccess initializeDrawingContext() override;
 
   /**
    * Removes references to native handles from this context and then returns
    * \return GHOST_kSuccess if it is OK for the parent to release the handles and
    * GHOST_kFailure if releasing the handles will interfere with sharing
    */
-  GHOST_TSuccess releaseNativeHandles();
+  GHOST_TSuccess releaseNativeHandles() override;
 
   /**
    * Sets the swap interval for #swapBuffers.
    * \param interval: The swap interval to use.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess setSwapInterval(int interval);
+  GHOST_TSuccess setSwapInterval(int interval) override;
 
   /**
    * Gets the current swap interval for #swapBuffers.
    * \param intervalOut: Variable to store the swap interval if it can be read.
    * \return Whether the swap interval can be read.
    */
-  GHOST_TSuccess getSwapInterval(int &intervalOut);
+  GHOST_TSuccess getSwapInterval(int &intervalOut) override;
 
   EGLDisplay getDisplay() const;
 
diff --git a/intern/ghost/intern/GHOST_ContextGLX.h b/intern/ghost/intern/GHOST_ContextGLX.h
index d526e6b1b32..e6b7309cbe9 100644
--- a/intern/ghost/intern/GHOST_ContextGLX.h
+++ b/intern/ghost/intern/GHOST_ContextGLX.h
@@ -41,52 +41,52 @@ class GHOST_ContextGLX : public GHOST_Context {
   /**
    * Destructor.
    */
-  ~GHOST_ContextGLX();
+  ~GHOST_ContextGLX() override;
 
   /**
    * Swaps front and back buffers of a window.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess swapBuffers();
+  GHOST_TSuccess swapBuffers() override;
 
   /**
    * Activates the drawing context of this window.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess activateDrawingContext();
+  GHOST_TSuccess activateDrawingContext() override;
 
   /**
    * Release the drawing context of the calling thread.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess releaseDrawingContext();
+  GHOST_TSuccess releaseDrawingContext() override;
 
   /**
    * Call immediately after new to initialize.  If this fails then immediately delete the object.
    * \return Indication as to whether initialization has succeeded.
    */
-  GHOST_TSuccess initializeDrawingContext();
+  GHOST_TSuccess initializeDrawingContext() override;
 
   /**
    * Removes references to native handles from this context and then returns
    * \return GHOST_kSuccess if it is OK for the parent to release the handles and
    * GHOST_kFailure if releasing the handles will interfere with sharing
    */
-  GHOST_TSuccess releaseNativeHandles();
+  GHOST_TSuccess releaseNativeHandles() override;
 
   /**
    * Sets the swap interval for #swapBuffers.
    * \param interval: The swap interval to use.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess setSwapInterval(int interval);
+  GHOST_TSuccess setSwapInterval(int interval) override;
 
   /**
    * Gets the current swap interval for #swapBuffers.
    * \param intervalOut: Variable to store the swap interval if it can be read.
    * \return Whether the swap interval can be read.
    */
-  GHOST_TSuccess getSwapInterval(int &intervalOut);
+  GHOST_TSuccess getSwapInterval(int &intervalOut) override;
 
  private:
   Display *m_display;
diff --git a/intern/ghost/intern/GHOST_ContextNone.h b/intern/ghost/intern/GHOST_ContextNone.h
index 4b0ad9448e8..c9cb97d57b5 100644
--- a/intern/ghost/intern/GHOST_ContextNone.h
+++ b/intern/ghost/intern/GHOST_ContextNone.h
@@ -21,50 +21,50 @@ class GHOST_ContextNone : public GHOST_Context {
    * Dummy function
    * \return Always succeeds
    */
-  GHOST_TSuccess swapBuffers();
+  GHOST_TSuccess swapBuffers() override;
 
   /**
    * Dummy function
    * \return Always succeeds.
    */
-  GHOST_TSuccess activateDrawingContext();
+  GHOST_TSuccess activateDrawingContext() override;
 
   /**
    * Dummy function
    * \return Always succeeds.
    */
-  GHOST_TSuccess releaseDrawingContext();
+  GHOST_TSuccess releaseDrawingContext() override;
 
   /**
    * Dummy function
    * \return Always succeeds.
    */
-  GHOST_TSuccess updateDrawingContext();
+  GHOST_TSuccess updateDrawingContext() override;
 
   /**
    * Dummy function
    * \return Always succeeds.
    */
-  GHOST_TSuccess initializeDrawingContext();
+  GHOST_TSuccess initializeDrawingContext() override;
 
   /**
    * Dummy function
    * \return Always succeeds.
    */
-  GHOST_TSuccess releaseNativeHandles();
+  GHOST_TSuccess releaseNativeHandles() override;
 
   /**
    * Dummy function
    * \return Always succeeds.
    */
-  GHOST_TSuccess setSwapInterval(int interval);
+  GHOST_TSuccess setSwapInterval(int interval) override;
 
   /**
    * Dummy function
    * \param intervalOut: Gets whatever was set by #setSwapInterval.
    * \return Always succeeds.
    */
-  GHOST_TSuccess getSwapInterval(int &intervalOut);
+  GHOST_TSuccess getSwapInterval(int &intervalOut) override;
 
  private:
   int m_swapInterval;
diff --git a/intern/ghost/intern/GHOST_ContextSDL.h b/intern/ghost/intern/GHOST_ContextSDL.h
index 8247ddff17b..9598cd2c9c8 100644
--- a/intern/ghost/intern/GHOST_ContextSDL.h
+++ b/intern/ghost/intern/GHOST_ContextSDL.h
@@ -41,52 +41,52 @@ class GHOST_ContextSDL : public GHOST_Context {
   /**
    * Destructor.
    */
-  ~GHOST_ContextSDL();
+  ~GHOST_ContextSDL() override;
 
   /**
    * Swaps front and back buffers of a window.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess swapBuffers();
+  GHOST_TSuccess swapBuffers() override;
 
   /**
    * Activates the drawing context of this window.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess activateDrawingContext();
+  GHOST_TSuccess activateDrawingContext() override;
 
   /**
    * Release the drawing context of the calling thread.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess releaseDrawingContext();
+  GHOST_TSuccess releaseDrawingContext() override;
 
   /**
    * Call immediately after new to initialize.  If this fails then immediately delete the object.
    * \return Indication as to whether initialization has succeeded.
    */
-  GHOST_TSuccess initializeDrawingContext();
+  GHOST_TSuccess initializeDrawingContext() override;
 
   /**
    * Removes references to native handles from this context and then returns
    * \return GHOST_kSuccess if it is OK for the parent to release the handles and
    * GHOST_kFailure if releasing the handles will interfere with sharing
    */
-  GHOST_TSuccess releaseNativeHandles();
+  GHOST_TSuccess releaseNativeHandles() override;
 
   /**
    * Sets the swap interval for #swapBuffers.
    * \param interval: The swap interval to use.
    * \return A boolean success indicator.
    */
-  GHOST_TSuccess setSwapInterval(int interval);
+  GHOST_TSuccess setSwapInterval(int interval) override;
 
   /**
    * Gets the current swap interval for #swapBuffers.
    * \param intervalOut: Variable to store the swap interval if it can be read.
    * \return Whether the swap interval can be read.
    */
-  GHOST_TSuccess getSwapInterval(int &intervalOut);
+  GHOST_TSuccess getSwapInterval(int &intervalOut) override;
 
  private:
   SDL_Window *m_window;
diff --git a/intern/ghost/intern/GHOST_SystemSDL.cpp b/intern/ghost/intern/GHOST_SystemSDL.cpp
index 05d6f96980b..4e82f1d10c8 100644
--- a/intern/ghost/intern/GHOST_SystemSDL.cpp
+++ b/intern/ghost/intern/GHOST_SystemSDL.cpp
@@ -770,7 +770,7 @@ void GHOST_SystemSDL::putClipboard(const char *buffer, bool /*selection*/) const
   SDL_SetClipboardText(buffer);
 }
 
-uint64_t GHOST_SystemSDL::getMilliSeconds()
+uint64_t GHOST_SystemSDL::getMilliSeconds() const
 {
   return uint64_t(SDL_GetTicks()); /* NOTE: 32 -> 64bits. */
 }
diff --git a/intern/ghost/intern/GHOST_SystemSDL.h b/intern/ghost/intern/GHOST_SystemSDL.h
index 36321757c0d..261fc2d2d68 100644
--- a/intern/ghost/intern/GHOST_SystemSDL.h
+++ b/intern/ghost/intern/GHOST_SystemSDL.h
@@ -31,41 +31,41 @@ class GHOST_SystemSDL : public GHOST_System {
   GHOST_SystemSDL();
   ~GHOST_SystemSDL();
 
-  bool processEvents(bool waitForEvent);
+  bool processEvents(bool waitForEvent) override;
 
-  bool setConsoleWindowState(GHOST_TConsoleWindowState /*action*/)
+  bool setConsoleWindowState(GHOST_TConsoleWindowState /*action*/) override
   {
     return false;
   }
 
-  GHOST_TSuccess getModifierKeys(GHOST_ModifierKeys &keys) const;
+  GHOST_TSuccess getModifierKeys(GHOST_ModifierKeys &keys) const override;
 
-  GHOST_TSuccess getButtons(GHOST_Buttons &buttons) const;
+  GHOST_TSuccess getButtons(GHOST_Buttons &buttons) const override;
 
-  GHOST_TCapabilityFlag getCapabilities() const;
+  GHOST_TCapabilityFlag getCapabilities() const override;
 
-  char *getClipboard(bool selection) const;
+  char *getClipboard(bool selection) const override;
 
-  void putClipboard(const char *buffer, bool selection) const;
+  void putClipboard(const char *buffer, bool selection) const override;
 
-  uint64_t getMilliSeconds();
+  uint64_t getMilliSeconds() const override;
 
-  uint8_t getNumDisplays() const;
+  uint8_t getNumDisplays() const override;
 
-  GHOST_TSuccess getCursorPosition(int32_t &x, int32_t &y) const;
+  GHOST_TSuccess getCursorPosition(int32_t &x, int32_t &y) const override;
 
-  GHOST_TSuccess setCursorPosition(int32_t x, int32_t y);
+  GHOST_TSuccess setCursorPosition(int32_t x, int32_t y) override;
 
-  void getAllDisplayDimensions(uint32_t &width, uint32_t &height) const;
+  void getAllDisplayDimensions(uint32_t &width, uint32_t &height) const override;
 
-  void getMainDisplayDimensions(uint32_t &width, uint32_t &height) const;
+  void getMainDisplayDimensions(uint32_t &width, uint32_t &height) const override;
 
-  GHOST_IContext *createOffscreenContext(GHOST_GLSettings glSettings);
+  GHOST_IContext *createOffscreenContext(GHOST_GLSettings glSettings) override;
 
-  GHOST_TSuccess disposeContext(GHOST_IContext *context);
+  GHOST_TSuccess disposeContext(GHOST_IContext *context) override;
 
  private:
-  GHOST_TSuccess init();
+  GHOST_TSuccess init() override;
 
   GHOST_IWindow *createWindow(const char *title,
                               int32_t left,
@@ -76,7 +76,7 @@ class GHOST_SystemSDL : public GHOST_System {
                               GHOST_GLSettings glSettings,
                               const bool exclusive = false,
                               const bool is_dialog = false,
-                              const GHOST_IWindow *parentWindow = NULL);
+                              const GHOST_IWindow *parentWindow = nullptr) override;
 
   /* SDL specific */
   GHOST_WindowSDL *findGhostWindow(SDL_Window *sdl_win);
diff --git a/intern/ghost/intern/GHOST_SystemX11.h b/intern/ghost/intern/GHOST_SystemX11.h
index 5f96dd49db6..a2e0f097d9f 100644
--- a/intern/ghost/intern/GHOST_SystemX11.h
+++ b/intern/ghost/intern/GHOST_SystemX11.h
@@ -69,9 +69,9 @@ class GHOST_SystemX11 : public GHOST_System {
   /**
    * Destructor.
    */
-  ~GHOST_SystemX11();
+  ~GHOST_SystemX11() override;
 
-  GHOST_TSuccess init();
+  GHOST_TSuccess init() override;
 
   /**
    * \section Interface Inherited from GHOST_ISystem
@@ -82,25 +82,25 @@ class GHOST_SystemX11 : public GHOST_System {
    * Returns the number of milliseconds since the start of the system process.
    * \return The number of milliseconds.
    */
-  uint64_t getMilliSeconds() const;
+  uint64_t getMilliSeconds() const override;
 
   /**
    * Returns the number of displays on this system.
    * \return The number of displays.
    */
-  uint8_t getNumDisplays() const;
+  uint8_t getNumDisplays() const override;
 
   /**
    * Returns the dimensions of the main display on this system.
    * \return The dimension of the main display.
    */
-  void getMainDisplayDimensions(uint32_t &width, uint32_t &height) const;
+  void getMainDisplayDimensions(uint32_t &width, uint32_t &height) const override;
 
   /**
    * Returns the dimensions of all displays on this system.
    * \return The dimension of the main display.
    */
-  void getAllDisplayDimensions(uint32_t &width, uint32_t &height) const;
+  void getAllDisplayDimensions(uint32_t &width, uint32_t &height) const override;
 
   /**
    * Create a new window.
@@ -127,48 +127,48 @@ class GHOST_SystemX11 : public GHOST_System {
                               GHOST_GLSettings glSettings,
                               const bool exclusive = false,
                               const bool is_dialog = false,
-                              const GHOST_IWindow *parentWindow = 0);
+                              const GHOST_IWindow *parentWindow = nullptr) override;
 
   /**
    * Create a new off-screen context.
    * Never explicitly delete the context, use #disposeContext() instead.
    * \return The new context (or 0 if creation failed).
    */
-  GHOST_IContext *createOffscreenContext(GHOST_GLSettings glSettings);
+  GHOST_IContext *createOffscreenContext(GHOST_GLSettings glSettings) override;
 
   /**
    * Dispose of a context.
    * \param context: Pointer to the context to be disposed.
    * \return Indication of success.
    */
-  GHOST_TSuccess disposeContext(GHOST_IContext *context);
+  GHOST_TSuccess disposeContext(GHOST_IContext *context) override;
 
   /**
    * Retrieves events from the system and stores them in the queue.
    * \param waitForEvent: Flag to wait for an event (or return immediately).
    * \return Indication of the presence of events.
    */
-  bool processEvents(bool waitForEvent);
+  bool processEvents(bool waitForEvent) override;
 
-  GHOST_TSuccess getCursorPosition(int32_t &x, int32_t &y) const;
+  GHOST_TSuccess getCursorPosition(int32_t &x, int32_t &y) const override;
 
-  GHOST_TSuccess setCursorPosition(int32_t x, int32_t y);
+  GHOST_TSuccess setCursorPosition(int32_t x, int32_t y) override;
 
   /**
    * Returns the state of all modifier keys.
    * \param keys: The state of all modifier keys (true == pressed).
    * \return Indication of success.
    */
-  GHOST_TSuccess getModifierKeys(GHOST_ModifierKeys &keys) const;
+  GHOST_TSuccess getModifierKeys(GHOST_ModifierKeys &keys) const override;
 
   /**
    * Returns the state of the mouse buttons (outside the message queue).
    * \param buttons: The state of the buttons.
    * \return Indication of success.
    */
-  GHOST_TSuccess getButtons(GHOST_Buttons &buttons) const;
+  GHOST_TSuccess getButtons(GHOST_Buttons &buttons) const override;
 
-  GHOST_TCapabilityFlag getCapabilities() const;
+  GHOST_TCapabilityFlag getCapabilities() const override;
 
   /**
    * Flag a window as dirty. This will
@@ -206,14 +206,14 @@ class GHOST_SystemX11 : public GHOST_System {
    * \param selection: Get selection, X11 only feature.
    * \return Returns the Clipboard indicated by Flag.
    */
-  char *getClipboard(bool selection) const;
+  char *getClipboard(bool selection) const override;
 
   /**
    * Puts buffer to system clipboard
    * \param buffer: The buffer to copy to the clipboard.
    * \param selection: Set the selection into the clipboard, X11 only feature.
    */
-  void putClipboard(const char *buffer, bool selection) const;
+  void putClipboard(const char *buffer, bool selection) const override;
 
   /**
    * Show a system message box
@@ -229,7 +229,7 @@ class GHOST_SystemX11 : public GHOST_System {
                                 const char *help_label,
                                 const char *continue_label,
                                 const char *link,
-                                GHOST_DialogOptions dialog_options) const;
+                                GHOST_DialogOptions dialog_options) const override;
 #ifdef WITH_XDND
   /**
    * Creates a drag'n'drop event and pushes it immediately onto the event queue.
@@ -253,7 +253,7 @@ class GHOST_SystemX11 : public GHOST_System {
   /**
    * \see GHOST_ISystem
    */
-  bool setConsoleWindowState(GHOST_TConsoleWindowState /*action*/)
+  bool setConsoleWindowState(GHOST_TConsoleWindowState /*action*/) override
   {
     return 0;
   }
diff --git a/intern/ghost/intern/GHOST_WindowSDL.h b/intern/ghost/intern/GHOST_WindowSDL.h
index 5805febab65..68daa44e774 100644
--- a/intern/ghost/intern/GHOST_WindowSDL.h
+++ b/intern/ghost/intern/GHOST_WindowSDL.h
@@ -42,7 +42,7 @@ class GHOST_WindowSDL : public GHOST_Window {
                   GHOST_TDrawingContextType type = GHOST_kDrawingContextTypeNone,
                   const bool stereoVisual = false,
                   const bool exclusive = false,
-                  const GHOST_IWindow *parentWindow = NULL);
+                  const GHOST_IWindow *parentWindow = nullptr);
 
   ~GHOST_WindowSDL();
 
@@ -52,7 +52,7 @@ class GHOST_WindowSDL : public GHOST_Window {
     return m_sdl_win;
   }
 
-  GHOST_TSuccess invalidate(void);
+  GHOST_TSuccess invalidate(void) override;
 
   /**
    * called by the X11 system implementation when expose events
@@ -64,22 +64,22 @@ class GHOST_WindowSDL : public GHOST_Window {
     m_invalid_window = false;
   }
 
-  bool getValid() const;
+  bool getValid() const override;
 
-  void getWindowBounds(GHOST_Rect &bounds) const;
-  void getClientBounds(GHOST_Rect &bounds) const;
+  void getWindowBounds(GHOST_Rect &bounds) const override;
+  void getClientBounds(GHOST_Rect &bounds) const override;
 
  protected:
   /**
    * \param type: The type of rendering context create.
    * \return Indication of success.
    */
-  GHOST_Context *newDrawingContext(GHOST_TDrawingContextType type);
+  GHOST_Context *newDrawingContext(GHOST_TDrawingContextType type) override;
 
-  GHOST_TSuccess setWindowCursorGrab(GHOST_TGrabCursorMode mode);
+  GHOST_TSuccess setWindowCursorGrab(GHOST_TGrabCursorMode mode) override;
 
-  GHOST_TSuccess setWindowCursorShape(GHOST_TStandardCursor shape);
-  GHOST_TSuccess hasCursorShape(GHOST_TStandardCursor shape);
+  GHOST_TSuccess setWindowCursorShape(GHOST_TStandardCursor shape) override;
+  GHOST_TSuccess hasCursorShape(GHOST_TStandardCursor shape) override;
 
   GHOST_TSuccess setWindowCustomCursorShape(uint8_t *bitmap,
                                             uint8_t *mask,
@@ -87,44 +87,44 @@ class GHOST_WindowSDL : public GHOST_Window {
                                             int sizey,
                                             int hotX,
                                             int hotY,
-                                            bool canInvertColor);
+                                            bool canInvertColor) override;
 
-  GHOST_TSuccess setWindowCursorVisibility(bool visible);
+  GHOST_TSuccess setWindowCursorVisibility(bool visible) override;
 
-  void setTitle(const char *title);
+  void setTitle(const char *title) override;
 
-  std::string getTitle() const;
+  std::string getTitle() const override;
 
-  GHOST_TSuccess setClientWidth(uint32_t width);
+  GHOST_TSuccess setClientWidth(uint32_t width) override;
 
-  GHOST_TSuccess setClientHeight(uint32_t height);
+  GHOST_TSuccess setClientHeight(uint32_t height) override;
 
-  GHOST_TSuccess setClientSize(uint32_t width, uint32_t height);
+  GHOST_TSuccess setClientSize(uint32_t width, uint32_t height) override;
 
-  void screenToClient(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const;
+  void screenToClient(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const override;
 
-  void clientToScreen(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const;
+  void clientToScreen(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const override;
 
-  GHOST_TSuccess setState(GHOST_TWindowState state);
+  GHOST_TSuccess setState(GHOST_TWindowState state) override;
 
-  GHOST_TWindowState getState() const;
+  GHOST_TWindowState getState() const override;
 
-  GHOST_TSuccess setOrder(GHOST_TWindowOrder /*order*/)
+  GHOST_TSuccess setOrder(GHOST_TWindowOrder /*order*/) override
   {
     // TODO
     return GHOST_kSuccess;
   }
 
   // TODO
-  GHOST_TSuccess beginFullScreen() const
+  GHOST_TSuccess beginFullScreen() const override
   {
     return GHOST_kFailure;
   }
 
-  GHOST_TSuccess endFullScreen() const
+  GHOST_TSuccess endFullScreen() const override
   {
     return GHOST_kFailure;
   }
 
-  uint16_t getDPIHint();
+  uint16_t getDPIHint() override;
 };
diff --git a/intern/ghost/intern/GHOST_WindowX11.h b/intern/ghost/intern/GHOST_WindowX11.h
index e9bee43c035..f9dac3b2ac7 100644
--- a/intern/ghost/intern/GHOST_WindowX11.h
+++ b/intern/ghost/intern/GHOST_WindowX11.h
@@ -63,44 +63,44 @@ class GHOST_WindowX11 : public GHOST_Window {
                   const bool exclusive = false,
                   const bool is_debug = false);
 
-  bool getValid() const;
+  bool getValid() const override;
 
-  void setTitle(const char *title);
+  void setTitle(const char *title) override;
 
-  std::string getTitle() const;
+  std::string getTitle() const override;
 
-  void getWindowBounds(GHOST_Rect &bounds) const;
+  void getWindowBounds(GHOST_Rect &bounds) const override;
 
-  void getClientBounds(GHOST_Rect &bounds) const;
+  void getClientBounds(GHOST_Rect &bounds) const override;
 
-  bool isDialog() const;
+  bool isDialog() const override;
 
-  GHOST_TSuccess setClientWidth(uint32_t width);
+  GHOST_TSuccess setClientWidth(uint32_t width) override;
 
-  GHOST_TSuccess setClientHeight(uint32_t height);
+  GHOST_TSuccess setClientHeight(uint32_t height) override;
 
-  GHOST_TSuccess setClientSize(uint32_t width, uint32_t height);
+  GHOST_TSuccess setClientSize(uint32_t width, uint32_t height) override;
 
-  void screenToClient(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const;
+  void screenToClient(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const override;
 
-  void clientToScreen(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const;
+  void clientToScreen(int32_t inX, int32_t inY, int32_t &outX, int32_t &outY) const override;
 
-  GHOST_TWindowState getState() const;
+  GHOST_TWindowState getState() const override;
 
-  GHOST_TSuccess setState(GHOST_TWindowState state);
+  GHOST_TSuccess setState(GHOST_TWindowState state) override;
 
-  GHOST_TSuccess setOrder(GHOST_TWindowOrder order);
+  GHOST_TSuccess setOrder(GHOST_TWindowOrder order) override;
 
-  GHOST_TSuccess invalidate();
+  GHOST_TSuccess invalidate() override;
 
-  GHOST_TSuccess setProgressBar(float progress);
-  GHOST_TSuccess endProgressBar();
+  GHOST_TSuccess setProgressBar(float progress) override;
+  GHOST_TSuccess endProgressBar() override;
 
   /**
    * Destructor.
    * Closes the window and disposes resources allocated.
    */
-  ~GHOST_WindowX11();
+  ~GHOST_WindowX11() override;
 
   /**
    * \section x11specific X11 system specific calls
@@ -152,32 +152,32 @@ class GHOST_WindowX11 : public GHOST_Window {
   bool m_post_init;
   GHOST_TWindowState m_post_state;
 
-  GHOST_TSuccess beginFullScreen() const;
+  GHOST_TSuccess beginFullScreen() const override;
 
-  GHOST_TSuccess endFullScreen() const;
+  GHOST_TSuccess endFullScreen() const override;
 
   GHOST_TSuccess setDialogHints(GHOST_WindowX11 *parentWindow);
 
-  uint16_t getDPIHint();
+  uint16_t getDPIHint() override;
 
  protected:
   /**
    * \param type: The type of rendering context create.
    * \return Indication of success.
    */
-  GHOST_Context *newDrawingContext(GHOST_TDrawingContextType type);
+  GHOST_Context *newDrawingContext(GHOST_TDrawingContextType type) override;
 
   /**
    * Sets the cursor visibility on the window using
    * native window system calls.
    */
-  GHOST_TSuccess setWindowCursorVisibility(bool visible);
+  GHOST_TSuccess setWindowCursorVisibility(bool visible) override;
 
   /**
    * Sets the cursor grab on the window using
    * native window system calls.
    */
-  GHOST_TSuccess setWindowCursorGrab(GHOST_TGrabCursorMode mode);
+  GHOST_TSuccess setWindowCursorGrab(GHOST_TGrabCursorMode mode) override;
 
   GHOST_TGrabCursorMode getWindowCursorGrab() const;
 
@@ -185,8 +185,8 @@ class GHOST_WindowX11 : public GHOST_Window {
    * Sets the cursor shape on the window using
    * native window system calls.
    */
-  GHOST_TSuccess setWindowCursorShape(GHOST_TStandardCursor shape);
-  GHOST_TSuccess hasCursorShape(GHOST_TStandardCursor shape);
+  GHOST_TSuccess setWindowCursorShape(GHOST_TStandardCursor shape) override;
+  GHOST_TSuccess hasCursorShape(GHOST_TStandardCursor shape) override;
 
   /**
    * Sets the cursor shape on the window using
@@ -198,7 +198,7 @@ class GHOST_WindowX11 : public GHOST_Window {
                                             int sizey,
                                             int hotX,
                                             int hotY,
-                                            bool canInvertColor);
+                                            bool canInvertColor) override;
 
  private:
   /* Force use of public constructor. */