diff --git a/platformio.ini b/platformio.ini
index c9eb6d5f4..04835d6c0 100755
--- a/platformio.ini
+++ b/platformio.ini
@@ -74,6 +74,7 @@ build_flags               = ${core_active.build_flags}
 build_unflags             = -Wall
 
 board_build.f_cpu         = 80000000L
+board_build.f_flash       = 40000000L
 monitor_speed             = 115200
 upload_speed              = 115200
 ; *** Upload Serial reset method for Wemos and NodeMCU
diff --git a/platformio_override_sample.ini b/platformio_override_sample.ini
index 22256f679..2becf05f7 100644
--- a/platformio_override_sample.ini
+++ b/platformio_override_sample.ini
@@ -52,6 +52,11 @@ build_flags               = ${core_active.build_flags}
 ; set CPU frequency to 80MHz (default) or 160MHz
 ;board_build.f_cpu         = 160000000L
 
+; set Flash chip frequency to 40MHz (default), 20MHz, 26Mhz, 80Mhz
+;board_build.f_flash       = 20000000L
+;board_build.f_flash       = 26000000L
+;board_build.f_flash       = 80000000L
+
 ; *** Upload Serial reset method for Wemos and NodeMCU
 upload_port               = COM5
 
@@ -165,6 +170,7 @@ board                   = esp32dev
 board_build.ldscript    = esp32_out.ld
 board_build.partitions  = esp32_partition_app1984k_spiffs64k.csv
 board_build.flash_mode  = ${common.board_build.flash_mode}
+board_build.f_flash     = ${common.board_build.f_flash}
 board_build.f_cpu       = ${common.board_build.f_cpu}
 build_unflags           = ${common.build_unflags}
                           -Wpointer-arith
diff --git a/platformio_tasmota_env.ini b/platformio_tasmota_env.ini
index dbf79d288..3d08d5cd6 100644
--- a/platformio_tasmota_env.ini
+++ b/platformio_tasmota_env.ini
@@ -5,6 +5,7 @@ framework = ${common.framework}
 board = ${common.board}
 board_build.ldscript  = ${common.board_build.ldscript}
 board_build.flash_mode = ${common.board_build.flash_mode}
+board_build.f_flash = ${common.board_build.f_flash}
 board_build.f_cpu = ${common.board_build.f_cpu}
 build_unflags = ${common.build_unflags}
 build_flags = ${common.build_flags}
diff --git a/platformio_tasmota_env32.ini b/platformio_tasmota_env32.ini
index f4f99282c..4398dcb04 100644
--- a/platformio_tasmota_env32.ini
+++ b/platformio_tasmota_env32.ini
@@ -6,6 +6,7 @@ board                   = ${common32.board}
 board_build.ldscript    = ${common32.board_build.ldscript}
 board_build.partitions  = ${common32.board_build.partitions}
 board_build.flash_mode  = ${common32.board_build.flash_mode}
+board_build.f_flash     = ${common32.board_build.f_flash}
 board_build.f_cpu       = ${common32.board_build.f_cpu}
 monitor_speed           = ${common32.monitor_speed}
 upload_port             = ${common32.upload_port}