diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/halconf.h b/libraries/AP_HAL_ChibiOS/hwdef/common/halconf.h
index 31e267e4d5..bf66f9bab2 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/halconf.h
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/halconf.h
@@ -147,7 +147,7 @@
  * @brief   Enables the RTC subsystem.
  */
 #if !defined(HAL_USE_RTC) || defined(__DOXYGEN__)
-#define HAL_USE_RTC                 FALSE
+#define HAL_USE_RTC                 TRUE
 #endif
 
 /**
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/iomcu/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/iomcu/hwdef.dat
index 70bf534af5..b2b49908ac 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/iomcu/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/iomcu/hwdef.dat
@@ -85,6 +85,7 @@ define PORT_INT_REQUIRED_STACK 64
 define __FPU_PRESENT 0
 
 define HAL_USE_ADC FALSE
+define HAL_USE_RTC FALSE
 define CH_DBG_ENABLE_CHECKS TRUE
 define CH_DBG_ENABLE_ASSERTS TRUE
 define CH_DBG_ENABLE_STACK_CHECK TRUE