diff --git a/include/android/surface_control.h b/include/android/surface_control.h
index 082387e..fb1419f 100644
--- a/include/android/surface_control.h
+++ b/include/android/surface_control.h
@@ -236,6 +236,10 @@
  * it is acquired. If no acquire_fence_fd was provided, this timestamp will be set to -1.
  *
  * Available since API level 29.
+ *
+ * @deprecated This may return SIGNAL_PENDING because the stats can arrive before the acquire
+ * fence has signaled, depending on internal timing differences. Therefore the caller should
+ * use the acquire fence passed in to setBuffer and query the signal time.
  */
 int64_t ASurfaceTransactionStats_getAcquireTime(ASurfaceTransactionStats* surface_transaction_stats,
                                                 ASurfaceControl* surface_control)