diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 931c446..05c24c5 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -318,6 +318,10 @@
         what |= eSidebandStreamChanged;
         sidebandStream = other.sidebandStream;
     }
+
+    if (other.what != what) {
+        ALOGE("Unmerged SurfaceComposer Transaction properties. LayerState::merge needs updating?");
+    }
 }
 
 }; // namespace android