diff --git a/include/gal/opengl/opengl_gal.h b/include/gal/opengl/opengl_gal.h
index a87973cfc8..e6cb3ca2f1 100644
--- a/include/gal/opengl/opengl_gal.h
+++ b/include/gal/opengl/opengl_gal.h
@@ -333,9 +333,9 @@ private:
 
     std::unique_ptr<GL_BITMAP_CACHE>         bitmapCache;
 
-    void lockContext();
+    void lockContext() override;
 
-    void unlockContext();
+    void unlockContext() override;
 
     ///< Update handler for OpenGL settings
     bool updatedGalDisplayOptions( const GAL_DISPLAY_OPTIONS& aOptions ) override;