diff --git a/packages/sysutils/busybox/scripts/init b/packages/sysutils/busybox/scripts/init
index aa61489f05..43e32c57cf 100755
--- a/packages/sysutils/busybox/scripts/init
+++ b/packages/sysutils/busybox/scripts/init
@@ -48,7 +48,7 @@ BREAK_TRIPPED="no"
 BIGFONT="1080"
 
 # Get a serial number if present (eg. RPi) otherwise use MAC address from eth0
-MACHINE_UID="$(cat /proc/cpuinfo | awk '/^Serial/{s=$3; gsub ("^0*","",s); print s}')"
+MACHINE_UID="$(awk '/^Serial/{s='0000000' $3; print substr(s, length(s) - 7)}' /proc/cpuinfo)"
 [ -z "$MACHINE_UID" ] && MACHINE_UID="$(cat /sys/class/net/eth0/address 2>/dev/null | tr -d :)"
 
 # common functions