diff --git a/Userland/Libraries/LibWeb/Painting/PaintableBox.h b/Userland/Libraries/LibWeb/Painting/PaintableBox.h
index f814e86a65..d6a2b9a491 100644
--- a/Userland/Libraries/LibWeb/Painting/PaintableBox.h
+++ b/Userland/Libraries/LibWeb/Painting/PaintableBox.h
@@ -163,7 +163,7 @@ private:
     Optional<BorderRadiusCornerClipper> mutable m_overflow_corner_radius_clipper;
 };
 
-class PaintableWithLines : public PaintableBox {
+class PaintableWithLines final : public PaintableBox {
     JS_CELL(PaintableWithLines, PaintableBox);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Painting/SVGGeometryPaintable.h b/Userland/Libraries/LibWeb/Painting/SVGGeometryPaintable.h
index a77ca45ee7..85060eef69 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGGeometryPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/SVGGeometryPaintable.h
@@ -11,7 +11,7 @@
 
 namespace Web::Painting {
 
-class SVGGeometryPaintable : public SVGGraphicsPaintable {
+class SVGGeometryPaintable final : public SVGGraphicsPaintable {
     JS_CELL(SVGGeometryPaintable, SVGGraphicsPaintable);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h b/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h
index dc7c6f1766..b09ce25ffd 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/SVGSVGPaintable.h
@@ -11,7 +11,7 @@
 
 namespace Web::Painting {
 
-class SVGSVGPaintable : public PaintableBox {
+class SVGSVGPaintable final : public PaintableBox {
     JS_CELL(SVGSVGPaintable, PaintableBox);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Painting/TextPaintable.h b/Userland/Libraries/LibWeb/Painting/TextPaintable.h
index e27ecb6b79..9213d6b4a4 100644
--- a/Userland/Libraries/LibWeb/Painting/TextPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/TextPaintable.h
@@ -10,7 +10,7 @@
 
 namespace Web::Painting {
 
-class TextPaintable : public Paintable {
+class TextPaintable final : public Paintable {
     JS_CELL(TextPaintable, Paintable);
 
 public: