diff --git a/platformio.ini b/platformio.ini
index 3d7a248b..a5b86642 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -821,6 +821,7 @@ build_flags = ${common.build_flags_esp8266}
 [env:esp8266_4MB_max] ;WLEDMM: WIP
 extends = env:d1_mini
 upload_speed = 460800 ;115200
+board_build.f_cpu = 160000000L    ;; we want 160Mhz (default = 80Mhz)
 build_flags = ${common.build_flags_esp8266}
   -D WLED_RELEASE_NAME=esp8266_4MB_max
   -D WLED_MAX_USERMODS=5 ; default only 4-6