diff --git a/libraries/AP_Motors/AP_MotorsMulticopter.cpp b/libraries/AP_Motors/AP_MotorsMulticopter.cpp
index d72966bfa0..2f039a83b0 100644
--- a/libraries/AP_Motors/AP_MotorsMulticopter.cpp
+++ b/libraries/AP_Motors/AP_MotorsMulticopter.cpp
@@ -760,7 +760,7 @@ void AP_MotorsMulticopter::set_throttle_passthrough_for_esc_calibration(float th
 // output a thrust to all motors that match a given motor mask. This
 // is used to control tiltrotor motors in forward flight. Thrust is in
 // the range 0 to 1
-void AP_MotorsMulticopter::output_motor_mask(float thrust, uint8_t mask, float rudder_dt)
+void AP_MotorsMulticopter::output_motor_mask(float thrust, uint16_t mask, float rudder_dt)
 {
     const int16_t pwm_min = get_pwm_output_min();
     const int16_t pwm_range = get_pwm_output_max() - pwm_min;
diff --git a/libraries/AP_Motors/AP_MotorsMulticopter.h b/libraries/AP_Motors/AP_MotorsMulticopter.h
index 3246d9586b..aa462db447 100644
--- a/libraries/AP_Motors/AP_MotorsMulticopter.h
+++ b/libraries/AP_Motors/AP_MotorsMulticopter.h
@@ -64,7 +64,7 @@ public:
     // output a thrust to all motors that match a given motor
     // mask. This is used to control tiltrotor motors in forward
     // flight. Thrust is in the range 0 to 1
-    virtual void        output_motor_mask(float thrust, uint8_t mask, float rudder_dt);
+    virtual void        output_motor_mask(float thrust, uint16_t mask, float rudder_dt);
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
diff --git a/libraries/AP_Motors/AP_MotorsTri.cpp b/libraries/AP_Motors/AP_MotorsTri.cpp
index ab734a8b15..6486ad8399 100644
--- a/libraries/AP_Motors/AP_MotorsTri.cpp
+++ b/libraries/AP_Motors/AP_MotorsTri.cpp
@@ -333,7 +333,7 @@ void AP_MotorsTri::thrust_compensation(void)
 /*
   override tricopter tail servo output in output_motor_mask
  */
-void AP_MotorsTri::output_motor_mask(float thrust, uint8_t mask, float rudder_dt)
+void AP_MotorsTri::output_motor_mask(float thrust, uint16_t mask, float rudder_dt)
 {
     // normal multicopter output
     AP_MotorsMulticopter::output_motor_mask(thrust, mask, rudder_dt);
diff --git a/libraries/AP_Motors/AP_MotorsTri.h b/libraries/AP_Motors/AP_MotorsTri.h
index 90b5f25b6c..1f6317ac6e 100644
--- a/libraries/AP_Motors/AP_MotorsTri.h
+++ b/libraries/AP_Motors/AP_MotorsTri.h
@@ -43,7 +43,7 @@ public:
     // mask. This is used to control tiltrotor motors in forward
     // flight. Thrust is in the range 0 to 1
     // rudder_dt applys diffential thrust for yaw in the range 0 to 1
-    void                output_motor_mask(float thrust, uint8_t mask, float rudder_dt) override;
+    void                output_motor_mask(float thrust, uint16_t mask, float rudder_dt) override;
 
     // return the roll factor of any motor, this is used for tilt rotors and tail sitters
     // using copter motors for forward flight