--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -3051,18 +3051,20 @@ TabChild::ClearCachedResources()
   mPuppetWidget->GetLayerManager()->ClearCachedResources();
 }
 
 void
 TabChild::InvalidateLayers()
 {
   MOZ_ASSERT(mPuppetWidget);
   MOZ_ASSERT(mPuppetWidget->GetLayerManager());
-  MOZ_ASSERT(mPuppetWidget->GetLayerManager()->GetBackendType() == LayersBackend::LAYERS_CLIENT
-             || mPuppetWidget->GetLayerManager()->GetBackendType() == LayersBackend::LAYERS_WR);
+  DebugOnly<LayersBackend> backend = mPuppetWidget->GetLayerManager()->GetBackendType();
+  MOZ_ASSERT(backend == LayersBackend::LAYERS_CLIENT ||
+             backend == LayersBackend::LAYERS_WR ||
+             backend == LayersBackend::LAYERS_BASIC);
 
   RefPtr<LayerManager> lm = mPuppetWidget->GetLayerManager();
   FrameLayerBuilder::InvalidateAllLayers(lm);
 }
 
 void
 TabChild::ReinitRendering()
 {