diff --git a/elements/growroot/static/usr/local/sbin/growroot b/elements/growroot/static/usr/local/sbin/growroot
index dfd85f544..7600a9db6 100755
--- a/elements/growroot/static/usr/local/sbin/growroot
+++ b/elements/growroot/static/usr/local/sbin/growroot
@@ -5,18 +5,12 @@ set -exu
 set -o pipefail
 
 root_dev=$(df -P / | tail -n 1 | awk '/.*/ { print $1 }')
-minor_dev_no=$(stat --printf="%T" $root_dev)
-major_dev_no=$(stat --printf="%t" $root_dev)
 
-# The last digit of our minor number should, on a partitioned block device,
-# be the partition number of the device (starting at 1). We need to convert
-# this value to decimal from hex for use in growpart.
-part_no=$(echo $minor_dev_no | tail -c 2)
-part_no=$((16#$part_no))
-
-disk=$(find /sys/dev/block -name "$((16#$major_dev_no)):${minor_dev_no::-1}0")
+disk=$(find /sys/dev/block -name $(udevadm info --query=all --name $root_dev | grep ID_PART_ENTRY_DISK | cut -d= -f2))
 disk="/dev/$(source ${disk}/uevent; echo $DEVNAME)"
 
+part_no=$(udevadm info --query=all --name $root_dev | grep ID_PART_ENTRY_NUMBER | cut -d= -f2)
+
 set +e
 growpart $disk $part_no
 # Error code 1 means no change