diff --git a/target/linux/mcs814x/image/Makefile b/target/linux/mcs814x/image/Makefile
index ac85474a2d..88c7af3a2a 100644
--- a/target/linux/mcs814x/image/Makefile
+++ b/target/linux/mcs814x/image/Makefile
@@ -11,6 +11,8 @@ TARGET_DTBS := rbt-832 dlan-usb-extender
 
 LOADADDR:=0x00008000
 
+JFFS2_BLOCKSIZE = 128k
+
 UIMAGE:=$(BIN_DIR)/$(IMG_PREFIX)-uImage
 ifeq ($(CONFIG_TARGET_ROOTFS_INITRAMFS),y)
 	UIMAGE:=$(BIN_DIR)/$(IMG_PREFIX)-uImage-initramfs