diff --git a/gfx/webrender_bindings/RenderCompositorSWGL.cpp b/gfx/webrender_bindings/RenderCompositorSWGL.cpp
index 1eec99bb3a72..e52b8eba50cd 100644
--- a/gfx/webrender_bindings/RenderCompositorSWGL.cpp
+++ b/gfx/webrender_bindings/RenderCompositorSWGL.cpp
@@ -57,13 +57,6 @@ bool RenderCompositorSWGL::MakeCurrent() {
 }
 
 bool RenderCompositorSWGL::BeginFrame() {
-  mRenderWidgetSize = Some(mWidget->GetClientSize());
-#ifdef MOZ_WAYLAND
-  if (mLastRenderWidgetSize != mRenderWidgetSize.value()) {
-    mLastRenderWidgetSize = mRenderWidgetSize.value();
-    mRequestFullRender = true;
-  }
-#endif
   // Set up a temporary region representing the entire window surface in case a
   // dirty region is not supplied.
   ClearMappedBuffer();
@@ -248,10 +241,7 @@ void RenderCompositorSWGL::CommitMappedBuffer(bool aDirty) {
   ClearMappedBuffer();
 }
 
-void RenderCompositorSWGL::CancelFrame() {
-  CommitMappedBuffer(false);
-  mRenderWidgetSize = Nothing();
-}
+void RenderCompositorSWGL::CancelFrame() { CommitMappedBuffer(false); }
 
 RenderedFrameId RenderCompositorSWGL::EndFrame(
     const nsTArray<DeviceIntRect>& aDirtyRects) {
@@ -260,7 +250,6 @@ RenderedFrameId RenderCompositorSWGL::EndFrame(
   // to EndRemoteDrawingInRegion as for StartRemoteDrawingInRegion.
   RenderedFrameId frameId = GetNextRenderFrameId();
   CommitMappedBuffer();
-  mRenderWidgetSize = Nothing();
   return frameId;
 }
 
@@ -289,11 +278,7 @@ bool RenderCompositorSWGL::Resume() {
 }
 
 LayoutDeviceIntSize RenderCompositorSWGL::GetBufferSize() {
-  // If we're between BeginFrame() and EndFrame()/CancelFrame() calls
-  // return recent rendering size instead of actual underlying widget
-  // size. It prevents possible rendering artifacts if widget size was changed.
-  return mRenderWidgetSize ? mRenderWidgetSize.value()
-                           : mWidget->GetClientSize();
+  return mWidget->GetClientSize();
 }
 
 void RenderCompositorSWGL::GetCompositorCapabilities(
diff --git a/gfx/webrender_bindings/RenderCompositorSWGL.h b/gfx/webrender_bindings/RenderCompositorSWGL.h
index 2b3ce3545420..7676a34858ba 100644
--- a/gfx/webrender_bindings/RenderCompositorSWGL.h
+++ b/gfx/webrender_bindings/RenderCompositorSWGL.h
@@ -63,16 +63,10 @@ class RenderCompositorSWGL : public RenderCompositor {
   void* mContext = nullptr;
   RefPtr<gfx::DrawTarget> mDT;
   LayoutDeviceIntRegion mDirtyRegion;
-  // Keep consistent buffer size between BeginFrame and EndFrame/CancelFrame
-  // calls to make sure we don't change buffer size during rendering.
-  Maybe<LayoutDeviceIntSize> mRenderWidgetSize;
   RefPtr<gfx::DataSourceSurface> mSurface;
   uint8_t* mMappedData = nullptr;
   int32_t mMappedStride = 0;
 #ifdef MOZ_WAYLAND
-  // On Wayland we need to request full render if widget size is changed
-  // because SW rendering backend reallocates and clears target surface.
-  LayoutDeviceIntSize mLastRenderWidgetSize;
   bool mRequestFullRender = false;
 #endif
 
diff --git a/widget/gtk/GtkCompositorWidget.cpp b/widget/gtk/GtkCompositorWidget.cpp
index 2c29d5de03eb..3a2dd3233ce4 100644
--- a/widget/gtk/GtkCompositorWidget.cpp
+++ b/widget/gtk/GtkCompositorWidget.cpp
@@ -48,7 +48,7 @@ GtkCompositorWidget::GtkCompositorWidget(
 #endif
 #if defined(MOZ_WAYLAND)
   if (GdkIsWaylandDisplay()) {
-    ConfigureWaylandBackend();
+    ConfigureWaylandBackend(mWidget);
     LOG("GtkCompositorWidget::GtkCompositorWidget() [%p] mWidget %p "
         "mIsRenderingSuspended %d\n",
         (void*)mWidget.get(), (void*)mWidget, !!mIsRenderingSuspended);
@@ -178,8 +178,8 @@ void GtkCompositorWidget::DisableRendering() {
 }
 
 #if defined(MOZ_WAYLAND)
-bool GtkCompositorWidget::ConfigureWaylandBackend() {
-  mProvider.Initialize(this);
+bool GtkCompositorWidget::ConfigureWaylandBackend(RefPtr<nsWindow> aWindow) {
+  mProvider.Initialize(aWindow);
   return true;
 }
 #endif
@@ -221,7 +221,7 @@ void GtkCompositorWidget::EnableRendering(const uintptr_t aXWindow,
 #if defined(MOZ_WAYLAND)
   if (GdkIsWaylandDisplay()) {
     LOG("  configure widget %p\n", mWidget.get());
-    if (!ConfigureWaylandBackend()) {
+    if (!ConfigureWaylandBackend(mWidget)) {
       return;
     }
   }
diff --git a/widget/gtk/GtkCompositorWidget.h b/widget/gtk/GtkCompositorWidget.h
index 601172d09ce6..bc1c3379cd69 100644
--- a/widget/gtk/GtkCompositorWidget.h
+++ b/widget/gtk/GtkCompositorWidget.h
@@ -99,7 +99,7 @@ class GtkCompositorWidget : public CompositorWidget,
 
  private:
 #if defined(MOZ_WAYLAND)
-  bool ConfigureWaylandBackend();
+  bool ConfigureWaylandBackend(RefPtr<nsWindow> aWindow);
 #endif
 #if defined(MOZ_X11)
   bool ConfigureX11Backend(Window aXWindow, bool aShaped);
diff --git a/widget/gtk/WindowSurfaceProvider.cpp b/widget/gtk/WindowSurfaceProvider.cpp
index faf147a80a4a..f8eee65cc58f 100644
--- a/widget/gtk/WindowSurfaceProvider.cpp
+++ b/widget/gtk/WindowSurfaceProvider.cpp
@@ -7,7 +7,6 @@
 #include "WindowSurfaceProvider.h"
 
 #include "gfxPlatformGtk.h"
-#include "GtkCompositorWidget.h"
 #include "mozilla/gfx/Logging.h"
 #include "mozilla/layers/LayersTypes.h"
 #include "nsWindow.h"
@@ -42,6 +41,10 @@ WindowSurfaceProvider::WindowSurfaceProvider()
     : mWindowSurface(nullptr),
       mMutex("WindowSurfaceProvider"),
       mWindowSurfaceValid(false)
+#ifdef MOZ_WAYLAND
+      ,
+      mWidget(nullptr)
+#endif
 #ifdef MOZ_X11
       ,
       mIsShaped(false),
@@ -57,11 +60,6 @@ void WindowSurfaceProvider::Initialize(RefPtr<nsWindow> aWidget) {
   mWindowSurfaceValid = false;
   mWidget = std::move(aWidget);
 }
-void WindowSurfaceProvider::Initialize(GtkCompositorWidget* aCompositorWidget) {
-  mWindowSurfaceValid = false;
-  mCompositorWidget = aCompositorWidget;
-  mWidget = static_cast<nsWindow*>(aCompositorWidget->RealWidget());
-}
 #endif
 #ifdef MOZ_X11
 void WindowSurfaceProvider::Initialize(Window aWindow, Visual* aVisual,
@@ -95,7 +93,7 @@ RefPtr<WindowSurface> WindowSurfaceProvider::CreateWindowSurface() {
     if (!mWidget) {
       return nullptr;
     }
-    return MakeRefPtr<WindowSurfaceWaylandMB>(mWidget, mCompositorWidget);
+    return MakeRefPtr<WindowSurfaceWaylandMB>(mWidget);
   }
 #endif
 #ifdef MOZ_X11
diff --git a/widget/gtk/WindowSurfaceProvider.h b/widget/gtk/WindowSurfaceProvider.h
index c7c7df42171a..a0d6315591c5 100644
--- a/widget/gtk/WindowSurfaceProvider.h
+++ b/widget/gtk/WindowSurfaceProvider.h
@@ -44,7 +44,6 @@ class WindowSurfaceProvider final {
    */
 #ifdef MOZ_WAYLAND
   void Initialize(RefPtr<nsWindow> aWidget);
-  void Initialize(GtkCompositorWidget* aCompositorWidget);
 #endif
 #ifdef MOZ_X11
   void Initialize(Window aWindow, Visual* aVisual, int aDepth, bool aIsShaped);
@@ -81,9 +80,6 @@ class WindowSurfaceProvider final {
   mozilla::Atomic<bool> mWindowSurfaceValid;
 #ifdef MOZ_WAYLAND
   RefPtr<nsWindow> mWidget;
-  // WindowSurfaceProvider is owned by GtkCompositorWidget so we don't need
-  // to reference it.
-  GtkCompositorWidget* mCompositorWidget = nullptr;
 #endif
 #ifdef MOZ_X11
   bool mIsShaped;
diff --git a/widget/gtk/WindowSurfaceWaylandMultiBuffer.cpp b/widget/gtk/WindowSurfaceWaylandMultiBuffer.cpp
index 85ab1942d9e6..c621f2ef6901 100644
--- a/widget/gtk/WindowSurfaceWaylandMultiBuffer.cpp
+++ b/widget/gtk/WindowSurfaceWaylandMultiBuffer.cpp
@@ -14,7 +14,6 @@
 #include "gfx2DGlue.h"
 #include "gfxPlatform.h"
 #include "MozContainer.h"
-#include "GtkCompositorWidget.h"
 #include "mozilla/gfx/DataSurfaceHelpers.h"
 #include "mozilla/gfx/Tools.h"
 #include "mozilla/ScopeExit.h"
@@ -153,29 +152,12 @@ using gfx::DataSourceSurface;
 
 #define BACK_BUFFER_NUM 3
 
-WindowSurfaceWaylandMB::WindowSurfaceWaylandMB(
-    RefPtr<nsWindow> aWindow, GtkCompositorWidget* aCompositorWidget)
+WindowSurfaceWaylandMB::WindowSurfaceWaylandMB(RefPtr<nsWindow> aWindow)
     : mSurfaceLock("WindowSurfaceWayland lock"),
       mWindow(std::move(aWindow)),
-      mCompositorWidget(aCompositorWidget),
       mFrameInProcess(false),
       mCallbackRequested(false) {}
 
-bool WindowSurfaceWaylandMB::MaybeUpdateWindowSize() {
-  // We want to get window size from compositor widget as it matches window
-  // size used by parent RenderCompositorSWGL rendrer.
-  // For main thread rendering mCompositorWidget is not available so get
-  // window size directly from nsWindow.
-  LayoutDeviceIntSize newWindowSize = mCompositorWidget
-                                          ? mCompositorWidget->GetClientSize()
-                                          : mWindow->GetClientSize();
-  if (mWindowSize != newWindowSize) {
-    mWindowSize = newWindowSize;
-    return true;
-  }
-  return false;
-}
-
 already_AddRefed<DrawTarget> WindowSurfaceWaylandMB::Lock(
     const LayoutDeviceIntRegion& aInvalidRegion) {
   MutexAutoLock lock(mSurfaceLock);
@@ -194,9 +176,11 @@ already_AddRefed<DrawTarget> WindowSurfaceWaylandMB::Lock(
 
   CollectPendingSurfaces(lock);
 
-  if (MaybeUpdateWindowSize()) {
-    LOGWAYLAND("  new window size [%d x %d]", mWindowSize.width,
-               mWindowSize.height);
+  LayoutDeviceIntSize newMozContainerSize = mWindow->GetMozContainerSize();
+  if (mMozContainerSize != newMozContainerSize) {
+    mMozContainerSize = newMozContainerSize;
+    LOGWAYLAND("  new MozContainer size [%d x %d]", mMozContainerSize.width,
+               mMozContainerSize.height);
     if (mInProgressBuffer) {
       ReturnBufferToPool(lock, mInProgressBuffer);
       mInProgressBuffer = nullptr;
@@ -212,7 +196,7 @@ already_AddRefed<DrawTarget> WindowSurfaceWaylandMB::Lock(
     if (mFrontBuffer && !mFrontBuffer->IsAttached()) {
       mInProgressBuffer = mFrontBuffer;
     } else {
-      mInProgressBuffer = ObtainBufferFromPool(lock, mWindowSize);
+      mInProgressBuffer = ObtainBufferFromPool(lock, mMozContainerSize);
       if (!mInProgressBuffer) {
         return nullptr;
       }
@@ -273,9 +257,9 @@ void WindowSurfaceWaylandMB::Commit(
   gfx::IntRect invalidRect = aInvalidRegion.GetBounds().ToUnknownRect();
   LOGWAYLAND(
       "WindowSurfaceWaylandMB::Commit [%p] damage rect [%d, %d] -> [%d x %d] "
-      "Window [%d x %d]\n",
+      "MozContainer [%d x %d]\n",
       (void*)mWindow.get(), invalidRect.x, invalidRect.y, invalidRect.width,
-      invalidRect.height, mWindowSize.width, mWindowSize.height);
+      invalidRect.height, mMozContainerSize.width, mMozContainerSize.height);
 #endif
 
   if (!mInProgressBuffer) {
@@ -357,7 +341,7 @@ void WindowSurfaceWaylandMB::ReturnBufferToPool(
     const RefPtr<WaylandBufferSHM>& aBuffer) {
   if (aBuffer->IsAttached()) {
     mPendingBuffers.AppendElement(aBuffer);
-  } else if (aBuffer->IsMatchingSize(mWindowSize)) {
+  } else if (aBuffer->IsMatchingSize(mMozContainerSize)) {
     mAvailableBuffers.AppendElement(aBuffer);
   }
   mInUseBuffers.RemoveElement(aBuffer);
@@ -381,7 +365,7 @@ void WindowSurfaceWaylandMB::CollectPendingSurfaces(
     const MutexAutoLock& aProofOfLock) {
   mPendingBuffers.RemoveElementsBy([&](auto& buffer) {
     if (!buffer->IsAttached()) {
-      if (buffer->IsMatchingSize(mWindowSize)) {
+      if (buffer->IsMatchingSize(mMozContainerSize)) {
         mAvailableBuffers.AppendElement(std::move(buffer));
       }
       return true;
diff --git a/widget/gtk/WindowSurfaceWaylandMultiBuffer.h b/widget/gtk/WindowSurfaceWaylandMultiBuffer.h
index e14a626de0ed..3e26a1d5b1ff 100644
--- a/widget/gtk/WindowSurfaceWaylandMultiBuffer.h
+++ b/widget/gtk/WindowSurfaceWaylandMultiBuffer.h
@@ -24,8 +24,7 @@ using gfx::DrawTarget;
 // and related management
 class WindowSurfaceWaylandMB : public WindowSurface {
  public:
-  WindowSurfaceWaylandMB(RefPtr<nsWindow> aWindow,
-                         GtkCompositorWidget* aCompositorWidget);
+  explicit WindowSurfaceWaylandMB(RefPtr<nsWindow> aWindow);
   ~WindowSurfaceWaylandMB() = default;
 
   // Lock() / Commit() are called by gecko when Firefox
@@ -54,16 +53,11 @@ class WindowSurfaceWaylandMB : public WindowSurface {
   void HandlePartialUpdate(const MutexAutoLock& aProofOfLock,
                            const LayoutDeviceIntRegion& aInvalidRegion);
   void IncrementBufferAge(const MutexAutoLock& aProofOfLock);
-  // Return true if window size was updated.
-  bool MaybeUpdateWindowSize();
 
   mozilla::Mutex mSurfaceLock MOZ_UNANNOTATED;
 
   RefPtr<nsWindow> mWindow;
-  // WindowSurfaceWaylandMB is owned by GtkCompositorWidget so we can't
-  // reference it.
-  GtkCompositorWidget* mCompositorWidget;
-  LayoutDeviceIntSize mWindowSize;
+  LayoutDeviceIntSize mMozContainerSize;
 
   RefPtr<WaylandBufferSHM> mInProgressBuffer;
   RefPtr<WaylandBufferSHM> mFrontBuffer;
diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
index f4a099a7c8b2..8b2cc893fa86 100644
--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -9660,6 +9660,18 @@ void nsWindow::SetEGLNativeWindowSize(
 }
 #endif
 
+LayoutDeviceIntSize nsWindow::GetMozContainerSize() {
+  LayoutDeviceIntSize size(0, 0);
+  if (mContainer) {
+    GtkAllocation allocation;
+    gtk_widget_get_allocation(GTK_WIDGET(mContainer), &allocation);
+    double scale = FractionalScaleFactor();
+    size.width = round(allocation.width * scale);
+    size.height = round(allocation.height * scale);
+  }
+  return size;
+}
+
 nsWindow* nsWindow::GetWindow(GdkWindow* window) {
   return get_window_for_gdk_window(window);
 }
diff --git a/widget/gtk/nsWindow.h b/widget/gtk/nsWindow.h
index ed01370563cc..1ae9b3f12616 100644
--- a/widget/gtk/nsWindow.h
+++ b/widget/gtk/nsWindow.h
@@ -274,6 +274,7 @@ class nsWindow final : public nsBaseWidget {
   static guint32 sLastButtonPressTime;
 
   MozContainer* GetMozContainer() { return mContainer; }
+  LayoutDeviceIntSize GetMozContainerSize();
   GdkWindow* GetGdkWindow() const { return mGdkWindow; };
   GdkWindow* GetToplevelGdkWindow() const;
   GtkWidget* GetGtkWidget() const { return mShell; }