diff --git a/ArduPlane/radio.pde b/ArduPlane/radio.pde
index ed3d1782b2..5b26479ce6 100644
--- a/ArduPlane/radio.pde
+++ b/ArduPlane/radio.pde
@@ -23,6 +23,7 @@ static void init_rc_in()
 	g.channel_throttle.dead_zone = 6;
 
 	//set auxiliary ranges
+	update_aux_servo_function(&g.rc_5, &g.rc_6, &g.rc_7, &g.rc_8);
 	G_RC_AUX(k_flap)->set_range(0,100);
 	G_RC_AUX(k_flap_auto)->set_range(0,100);
 	G_RC_AUX(k_aileron)->set_angle(SERVO_MAX);