diff --git a/drivers/mtd/devices/lart.c b/drivers/mtd/devices/lart.c
index a59584871af5..6d6502c2ec35 100644
--- a/drivers/mtd/devices/lart.c
+++ b/drivers/mtd/devices/lart.c
@@ -630,6 +630,7 @@ static int __init lart_flash_init (void)
    mtd.name = module_name;
    mtd.type = MTD_NORFLASH;
    mtd.writesize = 1;
+   mtd.writebufsize = 4;
    mtd.flags = MTD_CAP_NORFLASH;
    mtd.size = FLASH_BLOCKSIZE_PARAM * FLASH_NUMBLOCKS_16m_PARAM + FLASH_BLOCKSIZE_MAIN * FLASH_NUMBLOCKS_16m_MAIN;
    mtd.erasesize = FLASH_BLOCKSIZE_MAIN;