diff --git a/README.md b/README.md
index 83ff666b..fe8baef7 100644
--- a/README.md
+++ b/README.md
@@ -102,6 +102,7 @@ Paxcounter generates identifiers for sniffed MAC adresses and collects them temp
 - Quick blink (20ms on each 1/5 second): joining LoRaWAN network in progress or pending
 - Small blink (10ms on each 1/2 second): LoRaWAN data transmit in progress or pending
 - Long blink (200ms on each 2 seconds): LoRaWAN stack error
+- Single long flash (2ec): Known beacon detected
 
 **RGB LED:**
 
@@ -110,6 +111,7 @@ Paxcounter generates identifiers for sniffed MAC adresses and collects them temp
 - Yellow quick blink: joining LoRaWAN network in progress or pending
 - Blue blink: LoRaWAN data transmit in progress or pending
 - Red long blink: LoRaWAN stack error
+- White long blink: Known Beacon detected
 
 # Payload format
 
diff --git a/src/macsniff.cpp b/src/macsniff.cpp
index aa255456..0a997285 100644
--- a/src/macsniff.cpp
+++ b/src/macsniff.cpp
@@ -95,6 +95,9 @@ bool mac_add(uint8_t *paddr, int8_t rssi, bool sniff_type) {
       if (cfg.monitormode) {
         beaconID = isBeacon(addr2int);
         if (beaconID) {
+#if (HAS_LED != NOT_A_PIN) || defined(HAS_RGB_LED)
+          blink_LED(COLOR_WHITE, 2000);
+#endif
           payload.reset();
           payload.addAlarm(rssi, beaconID);
           senddata(BEACONPORT);