diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 5783c8d..e82d6f9 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -1424,6 +1424,11 @@
     TransactionHandler mTransactionHandler;
     display::DisplayMap<ui::LayerStack, frontend::DisplayInfo> mFrontEndDisplayInfos;
     bool mFrontEndDisplayInfosChanged = false;
+
+    // Layers visible during the last commit. This set should only be used for testing set equality
+    // and membership. The pointers should not be dereferenced as it's possible the set contains
+    // pointers to freed layers.
+    std::unordered_set<Layer*> mVisibleLayers;
 };
 
 class SurfaceComposerAIDL : public gui::BnSurfaceComposer {