diff --git a/include/timekeeper.h b/include/timekeeper.h
index fe4dfb9e..aa13d5ea 100644
--- a/include/timekeeper.h
+++ b/include/timekeeper.h
@@ -24,7 +24,12 @@ extern Ticker timesyncer;
 extern timesource_t timeSource;
 extern TaskHandle_t ClockTask;
 extern DRAM_ATTR bool TimePulseTick; // 1sec pps flag set by GPS or RTC
+#ifdef GPS_INT
 extern DRAM_ATTR unsigned long lastPPS;
+#endif
+#ifdef RTC_INT
+extern DRAM_ATTR unsigned long lastRTCpulse;
+#endif
 extern hw_timer_t *ppsIRQ;
 
 void setTimeSyncIRQ(void);
diff --git a/src/rtctime.cpp b/src/rtctime.cpp
index 50280d3b..0de8e176 100644
--- a/src/rtctime.cpp
+++ b/src/rtctime.cpp
@@ -52,9 +52,6 @@ uint8_t set_rtctime(time_t t) { // t is sec epoch time
   ESP_LOGI(TAG, "RTC time synced");
   return 1; // success
 
-  // failure
-  // return 0
-
 } // set_rtctime()
 
 time_t get_rtctime(uint16_t *msec) {
@@ -65,15 +62,18 @@ time_t get_rtctime(uint16_t *msec) {
     RtcDateTime tt = Rtc.GetDateTime();
     t = tt.Epoch32Time(); // sec2000 -> epoch
   }
-  /*
+
+// if we have a RTC pulse, we calculate msec
 #ifdef RTC_INT
-  // adjust time to top of next second by waiting TimePulseTick to flip
-  bool lastTick = TimePulseTick;
-  while (TimePulseTick == lastTick) {
-  };
-  t++;
+  uint16_t ppsDiff = millis() - lastRTCpulse;
+  if (ppsDiff < 1000)
+    *msec = ppsDiff;
+  else {
+    ESP_LOGD(TAG, "no pulse from RTC");
+    return 0;
+  }
 #endif
-*/
+
   return t;
 
 } // get_rtctime()
diff --git a/src/timekeeper.cpp b/src/timekeeper.cpp
index 896f49ec..ee0a4ed1 100644
--- a/src/timekeeper.cpp
+++ b/src/timekeeper.cpp
@@ -12,7 +12,13 @@ static const char TAG[] = __FILE__;
 const char timeSetSymbols[] = {'G', 'R', 'L', '*', '?'};
 
 DRAM_ATTR bool TimePulseTick = false;
+#ifdef GPS_INT
 DRAM_ATTR unsigned long lastPPS = millis();
+#endif
+#ifdef RTC_INT
+DRAM_ATTR unsigned long lastRTCpulse = millis();
+#endif
+
 timesource_t timeSource = _unsynced;
 TaskHandle_t ClockTask = NULL;
 hw_timer_t *ppsIRQ = NULL;
@@ -31,6 +37,7 @@ Ticker timesyncer;
 
 void setTimeSyncIRQ() { xTaskNotify(irqHandlerTask, TIMESYNC_IRQ, eSetBits); }
 
+#ifdef GPS_INT
 // interrupt service routine triggered by GPS PPS
 void IRAM_ATTR GPSIRQ(void) {
 
@@ -43,6 +50,7 @@ void IRAM_ATTR GPSIRQ(void) {
   if (xHigherPriorityTaskWoken)
     portYIELD_FROM_ISR();
 }
+#endif
 
 // interrupt service routine triggered by esp32 hardware timer
 void IRAM_ATTR CLOCKIRQ(void) {
@@ -60,6 +68,11 @@ void IRAM_ATTR CLOCKIRQ(void) {
   TimePulseTick = !TimePulseTick; // flip global variable pulse ticker
 #endif
 
+// take timestamp if we have RTC pulse
+#ifdef RTC_INT
+  lastRTCpulse = millis(); // last time of RTC pulse
+#endif
+
   // yield only if we should
   if (xHigherPriorityTaskWoken)
     portYIELD_FROM_ISR();
@@ -190,8 +203,10 @@ void timepulse_init(void) {
 #endif
 
   // get time if we don't have one
-  if (timeSource != _set)
+  if (timeSource != _set) {
+    delay(1000);      // wait for first PPS time stamp to arrive
     setTimeSyncIRQ(); // init systime by RTC or GPS or LORA
+  }
 
   // start cyclic time sync
   timesyncer.attach(TIME_SYNC_INTERVAL * 60, setTimeSyncIRQ);