diff --git a/ArduPlane/motor_test.cpp b/ArduPlane/motor_test.cpp
index 8774aa1833..cfc640cab9 100644
--- a/ArduPlane/motor_test.cpp
+++ b/ArduPlane/motor_test.cpp
@@ -7,8 +7,6 @@
  */
 
 // motor test definitions
-#define MOTOR_TEST_PWM_MIN              800     // min pwm value accepted by the test
-#define MOTOR_TEST_PWM_MAX              2200    // max pwm value accepted by the test
 #define MOTOR_TEST_TIMEOUT_MS_MAX       30000   // max timeout is 30 seconds
 
 // motor_test_output - checks for timeout and sends updates to motors objects
@@ -68,7 +66,7 @@ void QuadPlane::motor_test_output()
     }
 
     // sanity check throttle values
-    if (pwm >= MOTOR_TEST_PWM_MIN && pwm <= MOTOR_TEST_PWM_MAX ) {
+    if (pwm >= RC_Channel::RC_MIN_LIMIT_PWM && pwm <= RC_Channel::RC_MAX_LIMIT_PWM) {
         // turn on motor to specified pwm vlaue
         motors->output_test_seq(motor_test.seq, pwm);
     } else {