diff --git a/target/linux/adm5120/base-files/lib/upgrade/platform.sh b/target/linux/adm5120/base-files/lib/upgrade/platform.sh
index f067089fa17..fab2b3d7950 100644
--- a/target/linux/adm5120/base-files/lib/upgrade/platform.sh
+++ b/target/linux/adm5120/base-files/lib/upgrade/platform.sh
@@ -10,7 +10,7 @@ RAMFS_COPY_DATA=/lib/adm5120.sh
 platform_check_image() {
 	local magic="$(get_magic_word "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$board_name" in
 	"ZyXEL"*|"Compex WP54 family")
diff --git a/target/linux/adm8668/base-files/lib/upgrade/platform.sh b/target/linux/adm8668/base-files/lib/upgrade/platform.sh
index 583fa2e1dff..98e47ade318 100644
--- a/target/linux/adm8668/base-files/lib/upgrade/platform.sh
+++ b/target/linux/adm8668/base-files/lib/upgrade/platform.sh
@@ -1,6 +1,6 @@
 PART_NAME=linux
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$(get_magic_word "$1")" in
 		# u-boot
diff --git a/target/linux/ar71xx/base-files/lib/upgrade/platform.sh b/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
index 37ceea6073e..dfec1336fcd 100755
--- a/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
@@ -111,7 +111,7 @@ platform_check_image() {
 	local magic="$(get_magic_word "$1")"
 	local magic_long="$(get_magic_long "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$board" in
 	all0315n | \
diff --git a/target/linux/atheros/base-files/lib/upgrade/platform.sh b/target/linux/atheros/base-files/lib/upgrade/platform.sh
index d4daaacb951..d44b8fad809 100644
--- a/target/linux/atheros/base-files/lib/upgrade/platform.sh
+++ b/target/linux/atheros/base-files/lib/upgrade/platform.sh
@@ -31,7 +31,7 @@ platform_find_kernelpart() {
 }
 
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$(get_magic_word "$1")" in
 		# Combined Image
diff --git a/target/linux/au1000/base-files/lib/upgrade/platform.sh b/target/linux/au1000/base-files/lib/upgrade/platform.sh
index 71744e610be..1a9d151c8a2 100644
--- a/target/linux/au1000/base-files/lib/upgrade/platform.sh
+++ b/target/linux/au1000/base-files/lib/upgrade/platform.sh
@@ -2,7 +2,7 @@ KERNEL_IMG="openwrt-au1000-au1500-vmlinux.bin"
 ROOTFS_IMG="openwrt-au1000-au1500-root.fs"
 
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 	case "$(get_magic_word "$1")" in
 		6f70)
 			( get_image "$1" | tar -tf - $KERNEL_IMG >/dev/null && \
diff --git a/target/linux/avr32/base-files/lib/upgrade/platform.sh b/target/linux/avr32/base-files/lib/upgrade/platform.sh
index 00ad863d1bd..403a851c092 100755
--- a/target/linux/avr32/base-files/lib/upgrade/platform.sh
+++ b/target/linux/avr32/base-files/lib/upgrade/platform.sh
@@ -7,7 +7,7 @@ PART_NAME=firmware
 platform_check_image() {
 	local magic="$(get_magic_long "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	[ "$magic" != "27051956" ] && {
 		echo "Invalid image type."
diff --git a/target/linux/brcm47xx/base-files/lib/upgrade/platform.sh b/target/linux/brcm47xx/base-files/lib/upgrade/platform.sh
index 644f3c1e66c..48885b16329 100644
--- a/target/linux/brcm47xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/brcm47xx/base-files/lib/upgrade/platform.sh
@@ -1,7 +1,7 @@
 PART_NAME=firmware
 
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$(get_magic_word "$1")" in
 		# .trx files
diff --git a/target/linux/brcm63xx/base-files/lib/upgrade/platform.sh b/target/linux/brcm63xx/base-files/lib/upgrade/platform.sh
index 63ab77418ca..5c9e2c25f74 100644
--- a/target/linux/brcm63xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/brcm63xx/base-files/lib/upgrade/platform.sh
@@ -1,6 +1,6 @@
 PART_NAME=linux
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 	case "$(get_magic_word "$1")" in
 		3600|3700|3800)
 			# 6348GW-11 boards use openwrt-96348GW-11-squashfs-cfe.bin files
diff --git a/target/linux/cns21xx/base-files/lib/upgrade/platform.sh b/target/linux/cns21xx/base-files/lib/upgrade/platform.sh
index 52aa789f5b1..fd9bd289969 100755
--- a/target/linux/cns21xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/cns21xx/base-files/lib/upgrade/platform.sh
@@ -11,7 +11,7 @@ platform_check_image() {
 	local board=$(get_board_name)
 	local magic="$(get_magic_word "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$board" in
 	nsb3ast)
diff --git a/target/linux/cns3xxx/base-files/lib/upgrade/platform.sh b/target/linux/cns3xxx/base-files/lib/upgrade/platform.sh
index 599099181d7..6d94a5384d6 100644
--- a/target/linux/cns3xxx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/cns3xxx/base-files/lib/upgrade/platform.sh
@@ -69,7 +69,7 @@ platform_check_image() {
 	local magic="$(get_magic_word "$1")"
 	local magic_long="$(get_magic_long "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$board" in
 	laguna)
diff --git a/target/linux/ixp4xx/base-files/lib/upgrade/platform.sh b/target/linux/ixp4xx/base-files/lib/upgrade/platform.sh
index d10d9343704..508a167419e 100644
--- a/target/linux/ixp4xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ixp4xx/base-files/lib/upgrade/platform.sh
@@ -93,7 +93,7 @@ platform_check_image() {
 	local kern_part_size=0x$(platform_find_part_size "$kernelpart")
 	local kern_length=0x$(dd if="$1" bs=2 skip=1 count=4 2>/dev/null)
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$board" in
 	avila | cambria )
diff --git a/target/linux/lantiq/base-files/lib/upgrade/platform.sh b/target/linux/lantiq/base-files/lib/upgrade/platform.sh
index dc5bbe252eb..841566ea93d 100755
--- a/target/linux/lantiq/base-files/lib/upgrade/platform.sh
+++ b/target/linux/lantiq/base-files/lib/upgrade/platform.sh
@@ -1,7 +1,7 @@
 PART_NAME=firmware
 
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$(get_magic_word "$1")" in
 		# uImage
diff --git a/target/linux/mpc85xx/base-files/lib/upgrade/platform.sh b/target/linux/mpc85xx/base-files/lib/upgrade/platform.sh
index dbd179f5810..d95ec3013fe 100755
--- a/target/linux/mpc85xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/mpc85xx/base-files/lib/upgrade/platform.sh
@@ -28,7 +28,7 @@ platform_check_image() {
 	local board=$(mpc85xx_board_name)
 	local magic="$(get_magic_long "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case $board in
 	tl-wdr4900-v1)
diff --git a/target/linux/ppc40x/base-files/lib/upgrade/platform.sh b/target/linux/ppc40x/base-files/lib/upgrade/platform.sh
index ed08cab2a1e..b20b83cd57d 100644
--- a/target/linux/ppc40x/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ppc40x/base-files/lib/upgrade/platform.sh
@@ -11,7 +11,7 @@ platform_check_image() {
 	local board=$(ppc40x_board_name)
 	local magic="$(get_magic_word "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$board" in
 	kilauea | openrb | magicbox)
diff --git a/target/linux/ramips/base-files/lib/upgrade/platform.sh b/target/linux/ramips/base-files/lib/upgrade/platform.sh
index 3fdf6252822..190de9fbf1f 100755
--- a/target/linux/ramips/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ramips/base-files/lib/upgrade/platform.sh
@@ -11,7 +11,7 @@ platform_check_image() {
 	local board=$(ramips_board_name)
 	local magic="$(get_magic_long "$1")"
 
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$board" in
 	3g-6200n | \
diff --git a/target/linux/x86/base-files/lib/upgrade/platform.sh b/target/linux/x86/base-files/lib/upgrade/platform.sh
index 9503d5db88f..a2dd20a8810 100644
--- a/target/linux/x86/base-files/lib/upgrade/platform.sh
+++ b/target/linux/x86/base-files/lib/upgrade/platform.sh
@@ -14,7 +14,7 @@ x86_get_rootfs() {
 }
 
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$(get_magic_word "$1")" in
 		eb48|eb63) return 0;;
diff --git a/target/linux/x86/olpc/base-files/lib/upgrade/platform.sh b/target/linux/x86/olpc/base-files/lib/upgrade/platform.sh
index ffd0b93ab47..c90a4ce1c41 100644
--- a/target/linux/x86/olpc/base-files/lib/upgrade/platform.sh
+++ b/target/linux/x86/olpc/base-files/lib/upgrade/platform.sh
@@ -1,5 +1,5 @@
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$(get_magic_word "$1")" in
 		48eb) return 0;;
diff --git a/target/linux/x86_64/base-files/lib/upgrade/platform.sh b/target/linux/x86_64/base-files/lib/upgrade/platform.sh
index 9503d5db88f..a2dd20a8810 100644
--- a/target/linux/x86_64/base-files/lib/upgrade/platform.sh
+++ b/target/linux/x86_64/base-files/lib/upgrade/platform.sh
@@ -14,7 +14,7 @@ x86_get_rootfs() {
 }
 
 platform_check_image() {
-	[ "$ARGC" -gt 1 ] && return 1
+	[ "$#" -gt 1 ] && return 1
 
 	case "$(get_magic_word "$1")" in
 		eb48|eb63) return 0;;