diff --git a/ROMFS/px4fmu_common/init.d/rcS b/ROMFS/px4fmu_common/init.d/rcS
index 3d2a392541..64a1ed3c5f 100644
--- a/ROMFS/px4fmu_common/init.d/rcS
+++ b/ROMFS/px4fmu_common/init.d/rcS
@@ -765,6 +765,8 @@ then
 
 		# Arm straightaway.
 		pwm arm
+		# Use 400 Hz PWM on all channels.
+		pwm rate -a -r 400
 	fi
 
 	unset MIXER