diff --git a/libs/gui/VsyncEventData.cpp b/libs/gui/VsyncEventData.cpp
index 23f0921..76c60c2 100644
--- a/libs/gui/VsyncEventData.cpp
+++ b/libs/gui/VsyncEventData.cpp
@@ -23,6 +23,9 @@
 
 namespace android::gui {
 
+static_assert(VsyncEventData::kFrameTimelinesLength == 7,
+              "Must update value in DisplayEventReceiver.java#FRAME_TIMELINES_LENGTH (and here)");
+
 int64_t VsyncEventData::preferredVsyncId() const {
     return frameTimelines[preferredFrameTimelineIndex].vsyncId;
 }