diff --git a/libraries/AP_HAL_ChibiOS/hwdef/skyviper-f412-rev1/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/skyviper-f412-rev1/hwdef.dat
index d144fcec47..6526ee2498 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/skyviper-f412-rev1/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/skyviper-f412-rev1/hwdef.dat
@@ -9,6 +9,7 @@ APJ_BOARD_ID 9
 # crystal frequency
 OSCILLATOR_HZ 24000000
 
+define HAL_CUSTOM_CLOCK_TREE
 STM32_HSE_ENABLED FALSE
 STM32_PLLM_VALUE 16
 STM32_PLLN_VALUE 384