diff --git a/configs/at91sam9x5ek_dataflash_defconfig b/configs/at91sam9x5ek_dataflash_defconfig
index f00f3c8..923ed9a 100644
--- a/configs/at91sam9x5ek_dataflash_defconfig
+++ b/configs/at91sam9x5ek_dataflash_defconfig
@@ -36,6 +36,7 @@
 CONFIG_CMD_USB=y
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_CMD_DHCP=y
+CONFIG_BOOTP_BOOTFILESIZE=y
 CONFIG_CMD_PING=y
 CONFIG_CMD_FAT=y
 CONFIG_CMD_MTDPARTS=y