diff --git a/cpu/stm32f1/periph/rtc.c b/cpu/stm32f1/periph/rtc.c
index 41ca26a259..fc135765b5 100755
--- a/cpu/stm32f1/periph/rtc.c
+++ b/cpu/stm32f1/periph/rtc.c
@@ -115,12 +115,12 @@ static void _rtc_config(void)
     NVIC_EnableIRQ(RTC_Alarm_IRQn);
 }
 
-static time_t _rtc_get_time(void)
+static uint32_t _rtc_get_time(void)
 {
     return (RTC->CNTH << 16) | RTC->CNTL;
 }
 
-static void _rtc_set_time(time_t counter_val)
+static void _rtc_set_time(uint32_t counter_val)
 {
     _rtc_enter_config_mode();
     RTC->CNTH = (counter_val & 0xffff0000) >> 16;
@@ -132,7 +132,7 @@ void rtc_init(void)
 {
     /* save current time if RTC already works */
     bool is_rtc_enable = _is_rtc_enable();
-    time_t cur_time = 0;
+    uint32_t cur_time = 0;
     if (is_rtc_enable) {
         cur_time = _rtc_get_time();
     }
@@ -148,26 +148,21 @@ void rtc_init(void)
 
 int rtc_set_time(struct tm *time)
 {
-    time_t timestamp = mktime(time);
-
-    if (timestamp == -1) {
-        return -1;
-    }
+    uint32_t timestamp = rtc_mktime(time);
 
     _rtc_set_time(timestamp);
 
-    DEBUG("%s timestamp=%"PRIu32"\n", __func__, (uint32_t)timestamp);
+    DEBUG("%s timestamp=%"PRIu32"\n", __func__, timestamp);
 
     return 0;
 }
 
 int rtc_get_time(struct tm *time)
 {
-    time_t timestamp = _rtc_get_time();
-    localtime_r(&timestamp, time);
-
-    DEBUG("%s timestamp=%"PRIu32"\n", __func__, (uint32_t)timestamp);
+    uint32_t timestamp = _rtc_get_time();
+    rtc_localtime(timestamp, time);
 
+    DEBUG("%s timestamp=%"PRIu32"\n", __func__, timestamp);
     return 0;
 }
 
@@ -188,12 +183,12 @@ static void _rtc_disable_alarm(void)
     _rtc_exit_config_mode();
 }
 
-static time_t _rtc_get_alarm_time(void)
+static uint32_t _rtc_get_alarm_time(void)
 {
     return (RTC->ALRH << 16) | RTC->ALRL;
 }
 
-static void _rtc_set_alarm_time(time_t alarm_time)
+static void _rtc_set_alarm_time(uint32_t alarm_time)
 {
     _rtc_enter_config_mode();
     RTC->ALRL = (alarm_time & 0x0000ffff);
@@ -203,11 +198,7 @@ static void _rtc_set_alarm_time(time_t alarm_time)
 
 int rtc_set_alarm(struct tm *time, rtc_alarm_cb_t cb, void *arg)
 {
-    time_t timestamp = mktime(time);
-
-    if (timestamp == -1) {
-        return -2;
-    }
+    uint32_t timestamp = rtc_mktime(time);
 
     /* disable existing alarm (if enabled) */
     rtc_clear_alarm();
@@ -222,17 +213,17 @@ int rtc_set_alarm(struct tm *time, rtc_alarm_cb_t cb, void *arg)
     /* enable Alarm */
     _rtc_enable_alarm();
 
-    DEBUG("%s timestamp=%"PRIu32"\n", __func__, (uint32_t)timestamp);
+    DEBUG("%s timestamp=%"PRIu32"\n", __func__, timestamp);
 
     return 0;
 }
 
 int rtc_get_alarm(struct tm *time)
 {
-    time_t timestamp = _rtc_get_alarm_time();
-    localtime_r(&timestamp, time);
+    uint32_t timestamp = _rtc_get_alarm_time();
+    rtc_localtime(timestamp, time);
 
-    DEBUG("%s timestamp=%"PRIu32"\n", __func__, (uint32_t)timestamp);
+    DEBUG("%s timestamp=%"PRIu32"\n", __func__, timestamp);
 
     return 0;
 }