diff --git a/make/mcu/STM32H7.mk b/make/mcu/STM32H7.mk
index ff6aacad3..dabee4c80 100644
--- a/make/mcu/STM32H7.mk
+++ b/make/mcu/STM32H7.mk
@@ -159,22 +159,26 @@ DEVICE_FLAGS    = -DUSE_HAL_DRIVER -DUSE_DMA_RAM
 # H750xB : 128K FLASH, 1M RAM
 #
 ifeq ($(TARGET),$(filter $(TARGET),$(H743xI_TARGETS)))
-DEVICE_FLAGS   += -DSTM32H743xx
-LD_SCRIPT       = $(LINKER_DIR)/stm32_flash_h743_2m.ld
-STARTUP_SRC     = startup_stm32h743xx.s
-TARGET_FLASH   := 2048
+DEVICE_FLAGS       += -DSTM32H743xx
+DEFAULT_LD_SCRIPT   = $(LINKER_DIR)/stm32_flash_h743_2m.ld
+STARTUP_SRC         = startup_stm32h743xx.s
+TARGET_FLASH       := 2048
 else ifeq ($(TARGET),$(filter $(TARGET),$(H750xB_TARGETS)))
-DEVICE_FLAGS   += -DSTM32H750xx
-LD_SCRIPT       = $(LINKER_DIR)/stm32_flash_h750_128k.ld
-STARTUP_SRC     = startup_stm32h743xx.s
-TARGET_FLASH   := 128
+DEVICE_FLAGS       += -DSTM32H750xx
+DEFAULT_LD_SCRIPT   = $(LINKER_DIR)/stm32_flash_h750_128k.ld
+STARTUP_SRC         = startup_stm32h743xx.s
+DEFAULT_TARGET_FLASH := 128
+
+ifeq ($(TARGET_FLASH),)
+TARGET_FLASH := $(DEFAULT_TARGET_FLASH) 
+endif
 
 ifeq ($(EXST),yes)
-FIRMWARE_SIZE  := 448
+FIRMWARE_SIZE      := 448
 # TARGET_FLASH now becomes the amount of RAM memory that is occupied by the firmware
 # and the maximum size of the data stored on the external storage device.
-TARGET_FLASH   := FIRMWARE_SIZE
-LD_SCRIPT       = $(LINKER_DIR)/stm32_flash_h750_exst.ld
+TARGET_FLASH       := FIRMWARE_SIZE
+DEFAULT_LD_SCRIPT   = $(LINKER_DIR)/stm32_flash_h750_exst.ld
 endif
 
 ifneq ($(DEBUG),GDB)
@@ -189,6 +193,10 @@ else
 $(error Unknown MCU for H7 target)
 endif
 
+ifeq ($(LD_SCRIPT),)
+LD_SCRIPT = $(DEFAULT_LD_SCRIPT)
+endif
+
 ifneq ($(FIRMWARE_SIZE),)
 DEVICE_FLAGS   += -DFIRMWARE_SIZE=$(FIRMWARE_SIZE) 
 endif