diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h
index a03a409..cef5dd6 100644
--- a/include/hardware/sensors.h
+++ b/include/hardware/sensors.h
@@ -186,6 +186,7 @@
 #define SENSOR_STRING_TYPE_LOW_LATENCY_OFFBODY_DETECT   "android.sensor.low_latency_offbody_detect"
 #define SENSOR_STRING_TYPE_ACCELEROMETER_UNCALIBRATED   "android.sensor.accelerometer_uncalibrated"
 #define SENSOR_STRING_TYPE_HINGE_ANGLE                  "android.sensor.hinge_angle"
+#define SENSOR_STRING_TYPE_HEAD_TRACKER                 "android.sensor.head_tracker"
 
 /**
  * Values returned by the accelerometer in various locations in the universe.