diff --git a/targets/TARGET_STM/rtc_api.c b/targets/TARGET_STM/rtc_api.c
index ab3087df6d..eea48c02ae 100644
--- a/targets/TARGET_STM/rtc_api.c
+++ b/targets/TARGET_STM/rtc_api.c
@@ -55,8 +55,13 @@ void rtc_init(void)
     RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
 
     // Enable access to Backup domain
+    __HAL_RCC_PWR_CLK_ENABLE();
     HAL_PWR_EnableBkUpAccess();
 
+    if (rtc_isenabled()) {
+        return;
+    }
+
 #if !RTC_LSI /* => LSE */
     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE;
     RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // Mandatory, otherwise the PLL is reconfigured!
@@ -76,12 +81,7 @@ void rtc_init(void)
         error("PeriphClkInitStruct RTC failed with LSE\n");
     }
 
-    if (rtc_isenabled()) return;
 #else /*  => RTC_LSI */
-    if (rtc_isenabled()) return;
-
-    __HAL_RCC_PWR_CLK_ENABLE();
-
     // Reset Backup domain
     __HAL_RCC_BACKUPRESET_FORCE();
     __HAL_RCC_BACKUPRESET_RELEASE();