diff --git a/ports/mimxrt10xx/boards.h b/ports/mimxrt10xx/boards.h
index 05437d4f5..f6c82db46 100644
--- a/ports/mimxrt10xx/boards.h
+++ b/ports/mimxrt10xx/boards.h
@@ -48,7 +48,9 @@ extern uint32_t _board_boot_length[];
 #define BOARD_BOOT_LENGTH       ((uint32_t) _board_boot_length)
 
 // Flash Start Address of Application, typically 0x6000C000
+#ifndef BOARD_FLASH_APP_START
 #define BOARD_FLASH_APP_START   (FlexSPI_AMBA_BASE + 0xC000)
+#endif
 
 // Double Reset tap to enter DFU
 #define TINYUF2_DFU_DOUBLE_TAP  1