diff --git a/gfx/layers/composite/ContainerLayerComposite.cpp b/gfx/layers/composite/ContainerLayerComposite.cpp
index 555d3907abde..9e1b172cdedf 100644
--- a/gfx/layers/composite/ContainerLayerComposite.cpp
+++ b/gfx/layers/composite/ContainerLayerComposite.cpp
@@ -530,6 +530,10 @@ ContainerRender(ContainerT* aContainer,
     LayerManagerComposite::AutoAddMaskEffect autoMaskEffect(aContainer->GetMaskLayer(),
                                                             effectChain,
                                                             !aContainer->GetTransform().CanDraw2D());
+    if (autoMaskEffect.Failed()) {
+      NS_WARNING("Failed to apply a mask effect.");
+      return;
+    }
 
     aContainer->AddBlendModeEffect(effectChain);
     effectChain.mPrimaryEffect = new EffectRenderTarget(surface);
diff --git a/gfx/layers/composite/LayerManagerComposite.h b/gfx/layers/composite/LayerManagerComposite.h
index d5183186e55c..3955ec36214e 100644
--- a/gfx/layers/composite/LayerManagerComposite.h
+++ b/gfx/layers/composite/LayerManagerComposite.h
@@ -184,6 +184,7 @@ public:
                       bool aIs3D = false);
     ~AutoAddMaskEffect();
 
+    bool Failed() const { return !mCompositable; }
   private:
     CompositableHost* mCompositable;
   };