diff --git a/configs/at91sam9n12ek_mmc_defconfig b/configs/at91sam9n12ek_mmc_defconfig
index 998bacf..b84f924 100644
--- a/configs/at91sam9n12ek_mmc_defconfig
+++ b/configs/at91sam9n12ek_mmc_defconfig
@@ -28,6 +28,7 @@
 CONFIG_CMD_NAND_TRIMFFS=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