diff --git a/automotive/vehicle/aidl_property/aidl_api/android.hardware.automotive.vehicle.property/current/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl b/automotive/vehicle/aidl_property/aidl_api/android.hardware.automotive.vehicle.property/current/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl
index 44c9d54567..a24f515697 100644
--- a/automotive/vehicle/aidl_property/aidl_api/android.hardware.automotive.vehicle.property/current/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl
+++ b/automotive/vehicle/aidl_property/aidl_api/android.hardware.automotive.vehicle.property/current/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl
@@ -34,6 +34,7 @@
 package android.hardware.automotive.vehicle;
 @Backing(type="int") @VintfStability
 enum VehicleAreaSeat {
+  UNKNOWN = 0x0000,
   ROW_1_LEFT = 0x0001,
   ROW_1_CENTER = 0x0002,
   ROW_1_RIGHT = 0x0004,
diff --git a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl
index 89d50ea183..e70fb22717 100644
--- a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl
+++ b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleAreaSeat.aidl
@@ -22,6 +22,7 @@ package android.hardware.automotive.vehicle;
 @VintfStability
 @Backing(type="int")
 enum VehicleAreaSeat {
+    UNKNOWN = 0x0000,
     ROW_1_LEFT = 0x0001,
     ROW_1_CENTER = 0x0002,
     ROW_1_RIGHT = 0x0004,