diff --git a/src/modules/px4iofirmware/mixer.cpp b/src/modules/px4iofirmware/mixer.cpp
index 6a44294619..760ca2e27d 100644
--- a/src/modules/px4iofirmware/mixer.cpp
+++ b/src/modules/px4iofirmware/mixer.cpp
@@ -173,15 +173,16 @@ mixer_tick(void)
 	 * here.
 	 */
 	should_arm = (
-		/* IO initialised without error */   (r_status_flags & PX4IO_P_STATUS_FLAGS_INIT_OK)
-		/* and IO is armed */ 		  && (r_status_flags & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)
-		/* and FMU is armed */ 		  && (
-							    ((r_setup_arming & PX4IO_P_SETUP_ARMING_FMU_ARMED)
-		/* and there is valid input via or mixer */         &&   (r_status_flags & PX4IO_P_STATUS_FLAGS_MIXER_OK) )
-		/* or direct PWM is set */               || (r_status_flags & PX4IO_P_STATUS_FLAGS_RAW_PWM)
-		/* or failsafe was set manually */	 || ((r_setup_arming & PX4IO_P_SETUP_ARMING_FAILSAFE_CUSTOM) && !(r_status_flags & PX4IO_P_STATUS_FLAGS_FMU_OK))
-						     )
-	);
+				  (r_status_flags & PX4IO_P_STATUS_FLAGS_INIT_OK)/* IO initialised without error */
+				  && (r_status_flags & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)/* and IO is armed */
+				  && (
+						((r_setup_arming & PX4IO_P_SETUP_ARMING_FMU_ARMED)/* and FMU is armed */
+							&& (r_status_flags & PX4IO_P_STATUS_FLAGS_MIXER_OK))/* and there is valid input via or mixer */
+						|| (r_status_flags & PX4IO_P_STATUS_FLAGS_RAW_PWM)/* or direct PWM is set */
+						|| ((r_setup_arming & PX4IO_P_SETUP_ARMING_FAILSAFE_CUSTOM)
+							&& !(r_status_flags & PX4IO_P_STATUS_FLAGS_FMU_OK))/* or failsafe was set manually */
+					)
+				);
 
 	should_always_enable_pwm = (r_setup_arming & PX4IO_P_SETUP_ARMING_ALWAYS_PWM_ENABLE)
 						&& (r_status_flags & PX4IO_P_STATUS_FLAGS_INIT_OK)