diff --git a/cores/esp8266/core_esp8266_phy.c b/cores/esp8266/core_esp8266_phy.c
index a4a189384..ea0beefb1 100644
--- a/cores/esp8266/core_esp8266_phy.c
+++ b/cores/esp8266/core_esp8266_phy.c
@@ -261,7 +261,10 @@ void user_rf_pre_init() {
     // *((volatile uint32_t*) 0x60000710) = 0;
 
     volatile uint32_t* rtc_reg = (volatile uint32_t*) 0x60001000;
-    rtc_reg[30] = 0;
+    if((rtc_reg[24] >> 16) > 4) {
+        rtc_reg[24] &= 0xFFFF;
+        rtc_reg[30] = 0;
+    }
 
     system_set_os_print(0);
     __run_user_rf_pre_init();