diff --git a/include/gui/Surface.h b/include/gui/Surface.h
index af9dd50..37e2bec 100644
--- a/include/gui/Surface.h
+++ b/include/gui/Surface.h
@@ -371,6 +371,8 @@
     bool mSharedBufferHasBeenQueued;
 
     Condition mQueueBufferCondition;
+
+    uint64_t mNextFrameNumber;
 };
 
 namespace view {