diff --git a/automotive/vehicle/2.0/types.hal b/automotive/vehicle/2.0/types.hal
index 6232dd56da..955283e598 100644
--- a/automotive/vehicle/2.0/types.hal
+++ b/automotive/vehicle/2.0/types.hal
@@ -2478,7 +2478,7 @@ enum VehicleHvacFanDirection : int32_t {
     /**
      * FACE_AND_FLOOR = FACE | FLOOR
      */
-    FACE_AND_FLOOR = 0X3,
+    FACE_AND_FLOOR = 0x3,
     DEFROST = 0x4,
     /**
      * DEFROST_AND_FLOOR = DEFROST | FLOOR