diff --git a/ROMFS/px4fmu_common/init.d-posix/rcS b/ROMFS/px4fmu_common/init.d-posix/rcS
index 2f0d82ca18..5478a4afc6 100644
--- a/ROMFS/px4fmu_common/init.d-posix/rcS
+++ b/ROMFS/px4fmu_common/init.d-posix/rcS
@@ -30,6 +30,7 @@ set MIXER_FILE                  none
 set OUTPUT_MODE                 sim
 set EXTRA_MIXER_MODE            none
 set PWM_OUT                     none
+set PWM_AUX_OUT                 none
 set SDCARD_MIXERS_PATH          etc/mixers
 set USE_IO                      no
 set VEHICLE_TYPE                none