diff --git a/sonoff/_releasenotes.ino b/sonoff/_releasenotes.ino
index 4be23c8d7..725ce14e3 100644
--- a/sonoff/_releasenotes.ino
+++ b/sonoff/_releasenotes.ino
@@ -1,6 +1,7 @@
 /* 5.12.0m
  * Reinit timers to accomodate random window (#2447)
  * Remove sonoff-xxl
+ * Disable sleep when using Esp/Arduino core 2.4.1 (#2559)
  * Add sonoff-classic, sonoff-allsensors and sonoff-knx
  * Add some coloring to important web buttons
  * Add rule variables and teleperiod trigger to accomodate user HA messages
diff --git a/sonoff/support.ino b/sonoff/support.ino
index 8bc76d6a8..37e2139bb 100644
--- a/sonoff/support.ino
+++ b/sonoff/support.ino
@@ -615,7 +615,9 @@ void WifiBegin(uint8_t flag)
   delay(200);
   WiFi.mode(WIFI_STA);      // Disable AP mode
   if (Settings.sleep) {
+#ifndef ARDUINO_ESP8266_RELEASE_2_4_1     // See https://github.com/arendst/Sonoff-Tasmota/issues/2559
     WiFi.setSleepMode(WIFI_LIGHT_SLEEP);  // Allow light sleep during idle times
+#endif
   }
 //  if (WiFi.getPhyMode() != WIFI_PHY_MODE_11N) {
 //    WiFi.setPhyMode(WIFI_PHY_MODE_11N);