diff --git a/target/linux/apm821xx/image/Makefile b/target/linux/apm821xx/image/Makefile
index 38877f9bcaf..3ec8ae0cee8 100644
--- a/target/linux/apm821xx/image/Makefile
+++ b/target/linux/apm821xx/image/Makefile
@@ -69,7 +69,7 @@ define Device/mr24
   DEVICE_PACKAGES := kmod-spi-gpio kmod-ath9k wpad-mini
   DEVICE_PROFILE := MR24
   DEVICE_DTS := MR24
-  BLOCKSIZE := 64512
+  BLOCKSIZE := 63k
   IMAGES := sysupgrade.tar
   DTB_SIZE := 64512
   KERNEL_SIZE := 1984k
@@ -150,7 +150,7 @@ define Device/WNDR4700
   DEVICE_DTS := wndr4700
   PAGESIZE := 2048
   SUBPAGESIZE := 512
-  BLOCKSIZE := 131072
+  BLOCKSIZE := 128k
   DTB_SIZE := 131008
   IMAGE_SIZE:=25559040
   IMAGES := factory.img sysupgrade.tar
diff --git a/target/linux/bcm53xx/image/Makefile b/target/linux/bcm53xx/image/Makefile
index 22507b04809..2f45a7b4405 100644
--- a/target/linux/bcm53xx/image/Makefile
+++ b/target/linux/bcm53xx/image/Makefile
@@ -83,7 +83,7 @@ define Device/Default
   KERNEL_NAME := zImage
   IMAGE_NAME = $$(IMAGE_PREFIX)-$$(1).$$(2)
   IMAGES := trx
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   PAGESIZE := 2048
   UBINIZE_OPTS :=
   IMAGE/trx := append-ubi | trx-nand
diff --git a/target/linux/imx6/image/Makefile b/target/linux/imx6/image/Makefile
index ad89da8d820..86e3308c79f 100644
--- a/target/linux/imx6/image/Makefile
+++ b/target/linux/imx6/image/Makefile
@@ -100,7 +100,7 @@ define Device/ventana
   IMAGE/bootfs.tar.gz := bootfs.tar.gz | install-dtb
   IMAGE_NAME = $$(IMAGE_PREFIX)-$$(1)-$$(2)
   PAGESIZE := 2048
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   MKUBIFS_OPTS := -m $$(PAGESIZE) -e 124KiB
 endef
 
@@ -110,7 +110,7 @@ define Device/ventana-large
   DEVICE_TITLE := Gateworks Ventana family (large NAND flash)
   IMAGES := nand.ubi
   PAGESIZE := 4096
-  BLOCKSIZE := 256KiB
+  BLOCKSIZE := 256k
   MKUBIFS_OPTS := -m $$(PAGESIZE) -e 248KiB
 endef
 
diff --git a/target/linux/ipq806x/image/Makefile b/target/linux/ipq806x/image/Makefile
index 8c1064e552c..ff5be05d0d2 100644
--- a/target/linux/ipq806x/image/Makefile
+++ b/target/linux/ipq806x/image/Makefile
@@ -94,7 +94,7 @@ define Device/AP148
 	$(call Device/FitImage)
 	$(call Device/UbiFit)
 	DEVICE_DTS := qcom-ipq8064-ap148
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	PAGESIZE := 2048
 	BOARD_NAME := ap148
 	DEVICE_TITLE := Qualcomm AP148
@@ -105,7 +105,7 @@ define Device/AP148-legacy
 	$(call Device/LegacyImage)
 	$(call Device/UbiFit)
 	DEVICE_DTS := qcom-ipq8064-ap148
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	PAGESIZE := 2048
 	BOARD_NAME := ap148
 	DEVICE_TITLE := Qualcomm AP148 (legacy)
@@ -115,7 +115,7 @@ endef
 define Device/C2600
 	$(call Device/TpSafeImage)
 	DEVICE_DTS := qcom-ipq8064-c2600
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	PAGESIZE := 2048
 	BOARD_NAME := c2600
 	TPLINK_BOARD_NAME := C2600
@@ -129,7 +129,7 @@ define Device/D7800
 	KERNEL_SIZE := 2097152
 	NETGEAR_BOARD_ID := D7800
 	NETGEAR_HW_ID := 29764958+0+128+512+4x4+4x4
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	PAGESIZE := 2048
 	BOARD_NAME := d7800
 	DEVICE_TITLE := Netgear Nighthawk X4 D7800
@@ -149,7 +149,7 @@ define Device/EA8500
 	$(call Device/LegacyImage)
 	DEVICE_DTS := qcom-ipq8064-ea8500
 	PAGESIZE := 2048
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	KERNEL_SIZE := 3145728
 	FILESYSTEMS := squashfs
 	KERNEL = kernel-bin | append-dtb | uImage none | append-file $(KDIR)/root.dummy
@@ -168,7 +168,7 @@ define Device/R7500
 	KERNEL_SIZE := 2097152
 	NETGEAR_BOARD_ID := R7500
 	NETGEAR_HW_ID := 29764841+0+128+256+3x3+4x4
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	PAGESIZE := 2048
 	BOARD_NAME := r7500
 	DEVICE_TITLE := Netgear Nighthawk X4 R7500
@@ -181,7 +181,7 @@ define Device/R7500v2
 	KERNEL_SIZE := 2097152
 	NETGEAR_BOARD_ID := R7500v2
 	NETGEAR_HW_ID := 29764958+0+128+512+3x3+4x4
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	PAGESIZE := 2048
 	BOARD_NAME := r7500v2
 	DEVICE_TITLE := Netgear Nighthawk X4 R7500v2
@@ -194,7 +194,7 @@ define Device/R7800
 	KERNEL_SIZE := 2097152
 	NETGEAR_BOARD_ID := R7800
 	NETGEAR_HW_ID := 29764958+0+128+512+4x4+4x4+cascade
-	BLOCKSIZE := 128KiB
+	BLOCKSIZE := 128k
 	PAGESIZE := 2048
 	BOARD_NAME := r7800
 	DEVICE_TITLE := Netgear Nighthawk X4S R7800
diff --git a/target/linux/kirkwood/image/Makefile b/target/linux/kirkwood/image/Makefile
index 91b0495a436..33eaa4f4b25 100644
--- a/target/linux/kirkwood/image/Makefile
+++ b/target/linux/kirkwood/image/Makefile
@@ -26,7 +26,7 @@ define Device/Default
 
   PAGESIZE := 2048
   SUBPAGESIZE := 512
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   IMAGES := sysupgrade.tar
   IMAGE/sysupgrade.tar := sysupgrade-tar
 endef
diff --git a/target/linux/lantiq/image/Makefile b/target/linux/lantiq/image/Makefile
index 3c7391808dd..8e06a99c227 100644
--- a/target/linux/lantiq/image/Makefile
+++ b/target/linux/lantiq/image/Makefile
@@ -187,14 +187,14 @@ endef
 DEVICE_VARS += IMAGE_SIZE
 
 define Device/NAND/xway
-  BLOCKSIZE := 16KiB
+  BLOCKSIZE := 16k
   PAGESIZE := 512
   SUBPAGESIZE := 256
   FILESYSTEMS += ubifs
 endef
 
 define Device/NAND/xrx200
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   PAGESIZE := 2048
   SUBPAGESIZE := 512
   FILESYSTEMS += ubifs
diff --git a/target/linux/mvebu/image/Makefile b/target/linux/mvebu/image/Makefile
index 05321e1dc53..3d71e52f5bd 100644
--- a/target/linux/mvebu/image/Makefile
+++ b/target/linux/mvebu/image/Makefile
@@ -83,7 +83,7 @@ endef
 
 define Device/NAND-128K
   $(Device/UBI)
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   PAGESIZE := 2048
   SUBPAGESIZE := 512
   VID_HDR_OFFSET := 2048
@@ -91,13 +91,13 @@ endef
 
 define Device/NAND-256K
   $(Device/UBI)
-  BLOCKSIZE := 256KiB
+  BLOCKSIZE := 256k
   PAGESIZE := 4096
 endef
 
 define Device/NAND-512K
   $(Device/UBI)
-  BLOCKSIZE := 512KiB
+  BLOCKSIZE := 512k
   PAGESIZE := 4096
 endef
 
@@ -145,7 +145,7 @@ TARGET_DEVICES += linksys-wrt1900ac
 define Device/openblocks-ax3
   $(Device/UBI-factory)
   DEVICE_DTS := armada-xp-openblocks-ax3-4
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   PAGESIZE := 1
   IMAGE/factory.img := append-kernel $$$$(KERNEL_SIZE) | append-ubi
   DEVICE_TITLE := Plat'Home OpenBlocks AX3
diff --git a/target/linux/oxnas/image/Makefile b/target/linux/oxnas/image/Makefile
index bc691de4057..6e5bb82e6cf 100644
--- a/target/linux/oxnas/image/Makefile
+++ b/target/linux/oxnas/image/Makefile
@@ -29,7 +29,7 @@ define Device/Default
   KERNEL_INITRAMFS = kernel-bin | lzma | fit lzma $$(DTS_DIR)/ox820-$$(DTS).dtb | ubootable
   KERNEL_INITRAMFS_PREFIX = $$(IMAGE_PREFIX)-u-boot-initramfs
   KERNEL_INITRAMFS_SUFFIX := .bin
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   PAGESIZE := 2048
   SUBPAGESIZE := 512
   FILESYSTEMS := squashfs ubifs
diff --git a/target/linux/ramips/image/mt7621.mk b/target/linux/ramips/image/mt7621.mk
index e602dfb4091..d1d0aa43900 100644
--- a/target/linux/ramips/image/mt7621.mk
+++ b/target/linux/ramips/image/mt7621.mk
@@ -147,11 +147,11 @@ TARGET_DEVICES += zbt-wg3526
 
 define Device/wf-2881
   DTS := WF-2881
-  BLOCKSIZE := 128KiB
+  BLOCKSIZE := 128k
   PAGESIZE := 2048
   FILESYSTEMS := squashfs
   IMAGE_SIZE := 132382720
-  KERNEL := $(KERNEL_DTB) | pad-offset 131072 64 | uImage lzma
+  KERNEL := $(KERNEL_DTB) | pad-offset $$(BLOCKSIZE) 64 | uImage lzma
   IMAGE/sysupgrade.bin := append-kernel | append-ubi | check-size $$$$(IMAGE_SIZE)
   DEVICE_TITLE := NETIS WF-2881
   DEVICE_PACKAGES := kmod-usb3 kmod-ledtrig-usbdev