diff --git a/src/drivers/drv_mag.h b/src/drivers/drv_mag.h
index 06107bd3d1..a259ac9c06 100644
--- a/src/drivers/drv_mag.h
+++ b/src/drivers/drv_mag.h
@@ -81,6 +81,13 @@ struct mag_scale {
  */
 ORB_DECLARE(sensor_mag);
 
+
+/*
+ * mag device types, for _device_id
+ */
+#define DRV_MAG_DEVTYPE_HMC5883 1
+#define DRV_MAG_DEVTYPE_LSM303D 2
+
 /*
  * ioctl() definitions
  */