diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h
index 31434196bb..a8120d85c9 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h
@@ -130,25 +130,11 @@
 #define STM32_LSECLK   32768U
 #define STM32_LSEDRV   (3U << 3U)
 
-#ifndef STM32_PLLN_VALUE
-#define STM32_PLLN_VALUE                    336
-#endif
-#ifndef STM32_PLLP_VALUE
-#define STM32_PLLP_VALUE                    2
-#endif
-#ifndef STM32_PLLQ_VALUE
-#define STM32_PLLQ_VALUE                    7
-#endif
+#define STM32_VDD 330U
 
-#ifndef STM32_HPRE
 #define STM32_HPRE                          STM32_HPRE_DIV1
-#endif
-#ifndef STM32_PPRE1
 #define STM32_PPRE1                         STM32_PPRE1_DIV4
-#endif
-#ifndef STM32_PPRE2
 #define STM32_PPRE2                         STM32_PPRE2_DIV2
-#endif
 #define STM32_RTCSEL                        STM32_RTCSEL_LSI
 #define STM32_RTCPRE_VALUE                  8
 #define STM32_MCO1SEL                       STM32_MCO1SEL_HSI