diff --git a/include/android/sensor.h b/include/android/sensor.h
index 97b4a2a..43b991a 100644
--- a/include/android/sensor.h
+++ b/include/android/sensor.h
@@ -197,7 +197,7 @@
  * A sensor event.
  */
 
-/* NOTE: Must match hardware/sensors.h */
+/* NOTE: changes to these structs have to be backward compatible */
 typedef struct ASensorVector {
     union {
         float v[3];
@@ -259,7 +259,7 @@
     };
 } AAdditionalInfoEvent;
 
-/* NOTE: Must match hardware/sensors.h */
+/* NOTE: changes to this struct has to be backward compatible */
 typedef struct ASensorEvent {
     int32_t version; /* sizeof(struct ASensorEvent) */
     int32_t sensor;