diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h
index a8120d85c9..eef1f372d9 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32f47_mcuconf.h
@@ -85,7 +85,18 @@
 #if !defined(HAL_CUSTOM_CLOCK_TREE)
 #if defined(STM32F7xx_MCUCONF)
 // F7 clock config
-#if STM32_HSECLK == 8000000U
+#if STM32_HSECLK == 0U
+#undef STM32_HSE_ENABLED
+#undef STM32_HSI_ENABLED
+#undef STM32_PLLSRC
+#define STM32_HSE_ENABLED                   FALSE
+#define STM32_HSI_ENABLED                   TRUE
+#define STM32_PLLSRC                        STM32_PLLSRC_HSI
+#define STM32_PLLM_VALUE                    8
+#define STM32_PLLN_VALUE                    216
+#define STM32_PLLP_VALUE                    2
+#define STM32_PLLQ_VALUE                    9
+#elif STM32_HSECLK == 8000000U
 #define STM32_PLLM_VALUE                    8
 #define STM32_PLLN_VALUE                    432
 #define STM32_PLLP_VALUE                    2