diff --git a/libraries/AP_Motors/AP_MotorsHexa.cpp b/libraries/AP_Motors/AP_MotorsHexa.cpp
index a5f2d62b8f..0e55c13d28 100644
--- a/libraries/AP_Motors/AP_MotorsHexa.cpp
+++ b/libraries/AP_Motors/AP_MotorsHexa.cpp
@@ -46,4 +46,7 @@ void AP_MotorsHexa::setup_motors()
         add_motor(AP_MOTORS_MOT_5,  30, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1);
         add_motor(AP_MOTORS_MOT_6,-150, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  4);
     }
+
+    // normalise factors to magnitude 0.5
+    normalise_rpy_factors();
 }