diff --git a/target/linux/ar71xx/files/arch/mips/ar71xx/mach-dir-825-b1.c b/target/linux/ar71xx/files/arch/mips/ar71xx/mach-dir-825-b1.c
index 7762b5cdc5..80ab330844 100644
--- a/target/linux/ar71xx/files/arch/mips/ar71xx/mach-dir-825-b1.c
+++ b/target/linux/ar71xx/files/arch/mips/ar71xx/mach-dir-825-b1.c
@@ -68,6 +68,11 @@ static struct mtd_partition dir825b1_partitions[] = {
 		.offset		= 0x660000,
 		.size		= 0x010000,
 		.mask_flags	= MTD_WRITEABLE,
+	} , {
+		.name		= "unknown",
+		.offset		= 0x670000,
+		.size		= 0x190000,
+		.mask_flags	= MTD_WRITEABLE,
 	}
 };
 #endif /* CONFIG_MTD_PARTITIONS */
diff --git a/target/linux/ar71xx/image/Makefile b/target/linux/ar71xx/image/Makefile
index 94920a8030..746f52576e 100644
--- a/target/linux/ar71xx/image/Makefile
+++ b/target/linux/ar71xx/image/Makefile
@@ -77,7 +77,7 @@ define Image/Build/WRT400N
 	fi; fi
 endef
 
-dir825b1_mtdlayout=mtdparts=spi0.0:256k(uboot)ro,64k(config)ro,1024k(kernel),5184k(rootfs),64k(caldata)ro,6208k@0x50000(firmware)
+dir825b1_mtdlayout=mtdparts=spi0.0:256k(uboot)ro,64k(config)ro,1024k(kernel),5184k(rootfs),64k(caldata)ro,1600k(unknown)ro,6208k@0x50000(firmware)
 define Image/Build/DIR825B1
 	$(call PatchKernelLzma,$(2),$(3) $(dir825b1_mtdlayout))
 	$(call MkImageLzma,$(KDIR)/vmlinux-$(2).bin.lzma,$(call imgname,$(1),$(2)).bin)