diff --git a/platformio.ini b/platformio.ini
index 5dfd0a442..852db9128 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -62,7 +62,10 @@ board_build.f_cpu = 80000000L
 build_unflags = -Wall
 
 build_flags =
-  -Wl,-Tesp8266.flash.1m0.ld
+; if using esp8266 core 2.5.0 (stage) or up
+;  -Wl,-Tesp8266.flash.1m.ld -Wl,-Map,firmware.map
+; if using esp8266 core < 2.5.0
+  -Wl,-Tesp8266.flash.1m0.ld -Wl,-Map,firmware.map
   -mtarget-align
 ;  -DUSE_CONFIG_OVERRIDE  
 ; lwIP 1.4 (Default)