diff --git a/setup.sh b/setup.sh
index 607be91..2461db1 100755
--- a/setup.sh
+++ b/setup.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/zsh
 
 echo "Configuring macOS System Settings (you may be asked to enter password)"
 
@@ -57,18 +57,31 @@ echo "- Avoid creating .DS_Store files on external volumes"
 defaults write com.apple.desktopservices DSDontWriteNetworkStores -bool true
 defaults write com.apple.desktopservices DSDontWriteUSBStores -bool true
 
-# Install Homebrew
-/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
+# Check if Xcode CLI Tools are installed, install them if not
+if [[ $(xcode-select -p) == "" ]]; then
+    xcode-select --install
+else
+    echo "Xcode CLI Tools are already installed"
+fi
 
 # Set git to save any credentials in the macOS Keychain
 git config --global credential.helper osxkeychain
 
+# Check if Homebrew is present, update if installed, run the install script if not
+if [[ $(command -v brew) == "" ]]; then 
+	/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
+else
+    echo "Homebrew is already installed, running brew update"
+	brew update
+fi
+
 # Run Homebrew bundle with specified file
 brew bundle --file Brewfile
 # Run bash script to reconfigure Dock
 ./Dock.sh
 
-# Applescript to open up Terminal using the downloaded theme
+# Function to open up Terminal using the downloaded theme
+setCustomTerminalTheme(){
 cp Custom.terminal ~/Downloads/Custom.terminal
 osascript <<EOD
 tell application "Terminal"
@@ -78,10 +91,18 @@ tell application "Terminal"
     delay 1
 end tell
 EOD
-# Set theme to default
 defaults write com.apple.Terminal "Startup Window Settings" -string "Custom"
 defaults write com.apple.Terminal "Default Window Settings" -string "Custom"
 rm ~/Downloads/Custom.terminal
+}
+
+# Check if custom Terminal theme is already set and set up if not
+if [[ $(defaults read com.apple.Terminal "Startup Window Settings") !== "Custom" ]]; then
+    setCustomTerminalTheme
+    echo "Custom Terminal theme is now the default"
+else
+    echo "Custom Terminal theme is already set as default"
+fi
 
 #Copy ZSH Profile
 rsync zshrc ~/.zshrc