diff --git a/Package/Scripts/preinstall b/Package/Scripts/preinstall
index dad4d35..524e1d1 100755
--- a/Package/Scripts/preinstall
+++ b/Package/Scripts/preinstall
@@ -1,10 +1,10 @@
-#!/bin/sh
+#!/bin/zsh
 
 #  preinstall.sh
 #  Outset
 #
 #  Created by Bart Reardon on 25/3/2023.
-#  
+#
 
 ## Process legacy launchd items if upgrading from outset 3.0.3 or earlier
 
@@ -13,35 +13,35 @@ LA_ROOT="/Library/LaunchAgents"
 OUTSET_ROOT="/usr/local/outset"
 OUTSET_BACKUP="${OUTSET_ROOT}/backup"
 
-USER_ID=$(id -u $(stat -f %Su /dev/console))
+USER_ID=$(id -u "$(/usr/bin/stat -f %Su /dev/console)")
 
 ## LaunchDaemons
 DAEMONS=(
-  "${LD_ROOT}/com.github.outset.boot.plist"
-  "${LD_ROOT}/com.github.outset.cleanup.plist"
-  "${LD_ROOT}/com.github.outset.login-privileged.plist"
+    "${LD_ROOT}/com.github.outset.boot.plist"
+    "${LD_ROOT}/com.github.outset.cleanup.plist"
+    "${LD_ROOT}/com.github.outset.login-privileged.plist"
 )
 
 ## LaunchAgents
 AGENTS=(
-  "${LA_ROOT}/com.github.outset.login.plist"
-  "${LA_ROOT}/com.github.outset.on-demand.plist"
+    "${LA_ROOT}/com.github.outset.login.plist"
+    "${LA_ROOT}/com.github.outset.on-demand.plist"
 )
 
 # Unload if present
-for daemon in ${DAEMONS[@]}; do
+for daemon in $DAEMONS; do
     if [ -e "${daemon}" ]; then
         /bin/launchctl bootout system "${daemon}"
-        sudo rm -fv "${daemon}"
+        rm -fv "${daemon}"
     fi
 done
 
-for agent in ${AGENTS[@]}; do
+for agent in $AGENTS; do
     if [ -e "${agent}" ]; then
         if [ ${USER_ID} -ne 0 ]; then
-            launchctl bootout gui/${USER_ID} "${agent}"
+            /bin/launchctl bootout gui/${USER_ID} "${agent}"
         fi
-        sudo rm -fv "${agent}"
+        rm -fv "${agent}"
     fi
 done
 
@@ -52,7 +52,7 @@ if [ -d "${OUTSET_ROOT}/share" ]; then
     cp ${OUTSET_ROOT}/share/* "${OUTSET_BACKUP}/"
 fi
 
-for user in $(ls /Users); do
+for user in /Users/*; do
     if [ -e "/Users/${user}/Library/Preferences/com.github.outset.once.plist" ]; then
         mkdir -p "${OUTSET_ROOT}/backup/${user}"
         cp "/Users/${user}/Library/Preferences/com.github.outset.once.plist" "${OUTSET_BACKUP}/${user}/"