diff --git a/libraries/AP_HAL_ChibiOS/hwdef/CUAV-X7/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/CUAV-X7/hwdef.dat
index 8b41640436..60319bc61f 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/CUAV-X7/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/CUAV-X7/hwdef.dat
@@ -198,6 +198,8 @@ PF12 RSSI_IN ADC1 SCALE(1)
 PC5 VDD_5V_SENS ADC1 SCALE(2)
 PC1 SCALED_V3V3 ADC1 SCALE(2)
 
+PB1 FMU_SERVORAIL_VCC_SENS ADC1 SCALE(3)
+
 # CAN bus
 PI9  CAN1_RX CAN1
 PH13 CAN1_TX CAN1