diff --git a/ini/stm32f4.ini b/ini/stm32f4.ini
index 0e9dc9102a..c29e3180eb 100644
--- a/ini/stm32f4.ini
+++ b/ini/stm32f4.ini
@@ -639,7 +639,7 @@ upload_protocol             = jlink
 [env:mks_monster8_usb_flash_drive]
 extends           = env:mks_monster8
 platform_packages = ${stm_flash_drive.platform_packages}
-build_flags       = ${stm_flash_drive.build_flags} ${stm32f4_I2C1_CAN.build_flags} ${USB_HS_IN_FS.build_flags}
+build_flags       = ${env:mks_monster8.build_flags} ${stm_flash_drive.build_flags} ${stm32f4_I2C1_CAN.build_flags} ${USB_HS_IN_FS.build_flags}
 
 #
 # MKS Monster8 V1 / V2 (STM32F407VET6 ARM Cortex-M4) with USB Flash Drive Support and Shared Media