diff --git a/libraries/GCS_MAVLink/message_definitions/ardupilotmega.xml b/libraries/GCS_MAVLink/message_definitions/ardupilotmega.xml
index a9c883ddd3cf3a171f616723ed6ea7fa35643f08..7149894d6bb1ded605d7404a52bdfa126ad6d114 100644
--- a/libraries/GCS_MAVLink/message_definitions/ardupilotmega.xml
+++ b/libraries/GCS_MAVLink/message_definitions/ardupilotmega.xml
@@ -100,6 +100,17 @@
           <param index="7">Empty</param>
       </entry>
 
+      <entry name="MAV_CMD_DO_MOTOR_TEST" value="209">
+          <description>Mission command to perform motor test</description>
+          <param index="1">motor sequence number (a number from 1 to max number of motors on the vehicle)</param>
+          <param index="2">throttle type (0=throttle percentage, 1=PWM, 2=pilot throttle channel pass-through. See MOTOR_TEST_THROTTLE_TYPE enum)</param>
+          <param index="3">throttle</param>
+          <param index="4">timeout (in seconds)</param>
+          <param index="5">Empty</param>
+          <param index="6">Empty</param>
+          <param index="7">Empty</param>
+      </entry>
+
 	  </enum>
 
 	  <!-- fenced mode enums -->
@@ -170,6 +181,19 @@
         </entry>
     </enum>
 
+    <!-- motor test type enum -->
+    <enum name="MOTOR_TEST_THROTTLE_TYPE">
+        <entry name="MOTOR_TEST_THROTTLE_PERCENT" value="0">
+        <description>throttle as a percentage from 0 ~ 100</description>
+        </entry>
+        <entry name="MOTOR_TEST_THROTTLE_PWM" value="1">
+        <description>throttle as an absolute PWM value (normally in range of 1000~2000)</description>
+        </entry>
+        <entry name="MOTOR_TEST_THROTTLE_PILOT" value="2">
+        <description>throttle pass-through from pilot's transmitter</description>
+        </entry>
+    </enum>
+
       </enums>
 
      <messages>