diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
index 4ef3c7d84d..4a401a24af 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
@@ -961,6 +961,8 @@ def write_UART_config(f):
         )
         uart_list.append(config['IOMCU_UART'][0])
         f.write('#define HAL_HAVE_SERVO_VOLTAGE 1\n') # make the assumption that IO gurantees servo monitoring
+        # all IOMCU capable boards have SBUS out
+        f.write('#define AP_FEATURE_SBUS_OUT 1\n')
     else:
         f.write('#define HAL_WITH_IO_MCU 0\n')
     f.write('\n')