diff --git a/arch/arm/src/stm32l4/stm32l4_rcc.c b/arch/arm/src/stm32l4/stm32l4_rcc.c
index d18e0dbc882..1f90867dc31 100644
--- a/arch/arm/src/stm32l4/stm32l4_rcc.c
+++ b/arch/arm/src/stm32l4/stm32l4_rcc.c
@@ -56,6 +56,7 @@
 #include "stm32l4_flash.h"
 #include "stm32l4.h"
 #include "stm32l4_waste.h"
+#include "stm32l4_rtc.h"
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -117,8 +118,18 @@ static inline void rcc_resetbkp(void)
   /* Check if the RTC is already configured */
 
   init_stat = stm32l4_rtc_is_initialized();
-  if(!init_stat)
+  if (!init_stat)
     {
+      uint32_t bkregs[STM32L4_RTC_BKCOUNT];
+      int i;
+
+      /* Backup backup-registers before RTC reset. */
+
+      for (i = 0; i < STM32L4_RTC_BKCOUNT; i++)
+        {
+          bkregs[i] = getreg32(STM32L4_RTC_BKR(i));
+        }
+
        /* Enable write access to the backup domain (RTC registers, RTC
         * backup data registers and backup SRAM).
         */
@@ -132,6 +143,18 @@ static inline void rcc_resetbkp(void)
        modifyreg32(STM32L4_RCC_BDCR, 0, RCC_BDCR_BDRST);
        modifyreg32(STM32L4_RCC_BDCR, RCC_BDCR_BDRST, 0);
 
+       /* Restore backup-registers, except RTC related. */
+
+       for (i = 0; i < STM32L4_RTC_BKCOUNT; i++)
+         {
+           if (RTC_MAGIC_REG == STM32L4_RTC_BKR(i))
+             {
+               continue;
+             }
+
+           putreg32(bkregs[i], STM32L4_RTC_BKR(i));
+         }
+
        (void)stm32l4_pwr_enablebkp(false);
     }
 }
diff --git a/arch/arm/src/stm32l4/stm32l4_rtc.c b/arch/arm/src/stm32l4/stm32l4_rtc.c
index 7707d264c5f..f083250c7b9 100644
--- a/arch/arm/src/stm32l4/stm32l4_rtc.c
+++ b/arch/arm/src/stm32l4/stm32l4_rtc.c
@@ -84,22 +84,6 @@
 #  error "CONFIG_STM32L4_PWR must selected to use this driver"
 #endif
 
-#if !defined(CONFIG_RTC_MAGIC)
-# define CONFIG_RTC_MAGIC (0xfacefeee)
-#endif
-
-#if !defined(CONFIG_RTC_MAGIC_TIME_SET)
-#  define CONFIG_RTC_MAGIC_TIME_SET (CONFIG_RTC_MAGIC + 1)
-#endif
-
-#if !defined(CONFIG_RTC_MAGIC_REG)
-# define CONFIG_RTC_MAGIC_REG (0)
-#endif
-
-#define RTC_MAGIC            CONFIG_RTC_MAGIC
-#define RTC_MAGIC_TIME_SET   CONFIG_RTC_MAGIC_TIME_SET
-#define RTC_MAGIC_REG        STM32L4_RTC_BKR(CONFIG_RTC_MAGIC_REG)
-
 /* Constants ****************************************************************/
 
 #define SYNCHRO_TIMEOUT  (0x00020000)
diff --git a/arch/arm/src/stm32l4/stm32l4_rtc.h b/arch/arm/src/stm32l4/stm32l4_rtc.h
index c7da87e212f..e7b06fcb31c 100644
--- a/arch/arm/src/stm32l4/stm32l4_rtc.h
+++ b/arch/arm/src/stm32l4/stm32l4_rtc.h
@@ -57,6 +57,22 @@
 #define STM32L4_RTC_PRESCALER_SECOND  32767  /* Default prescaler to get a second base */
 #define STM32L4_RTC_PRESCALER_MIN         1  /* Maximum speed of 16384 Hz */
 
+#if !defined(CONFIG_RTC_MAGIC)
+# define CONFIG_RTC_MAGIC (0xfacefeee)
+#endif
+
+#if !defined(CONFIG_RTC_MAGIC_TIME_SET)
+#  define CONFIG_RTC_MAGIC_TIME_SET (CONFIG_RTC_MAGIC + 1)
+#endif
+
+#if !defined(CONFIG_RTC_MAGIC_REG)
+# define CONFIG_RTC_MAGIC_REG (0)
+#endif
+
+#define RTC_MAGIC            CONFIG_RTC_MAGIC
+#define RTC_MAGIC_TIME_SET   CONFIG_RTC_MAGIC_TIME_SET
+#define RTC_MAGIC_REG        STM32L4_RTC_BKR(CONFIG_RTC_MAGIC_REG)
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/