diff --git a/subsys/dfu/boot/mcuboot.c b/subsys/dfu/boot/mcuboot.c
index 381f2be6422..9a0103b050a 100644
--- a/subsys/dfu/boot/mcuboot.c
+++ b/subsys/dfu/boot/mcuboot.c
@@ -67,7 +67,7 @@ struct mcuboot_v1_raw_header {
 #define BOOT_FLAG_IMAGE_OK 0
 #define BOOT_FLAG_COPY_DONE 1
 
-#define FLASH_MIN_WRITE_SIZE FLASH_WRITE_BLOCK_SIZE
+#define FLASH_MIN_WRITE_SIZE DT_FLASH_WRITE_BLOCK_SIZE
 
 /* DT_FLASH_AREA_IMAGE_XX_YY values used below are auto-generated by DT */
 #define FLASH_BANK0_ID DT_FLASH_AREA_IMAGE_0_ID