diff --git a/services/surfaceflinger/TransactionState.h b/services/surfaceflinger/TransactionState.h
index f1ef31d..7bde2c1 100644
--- a/services/surfaceflinger/TransactionState.h
+++ b/services/surfaceflinger/TransactionState.h
@@ -33,6 +33,7 @@
     ResolvedComposerState() = default;
     ResolvedComposerState(ComposerState&& source) { state = std::move(source.state); }
     std::shared_ptr<renderengine::ExternalTexture> externalTexture;
+    int hwcBufferSlot = 0;
 };
 
 struct TransactionState {