diff --git a/Scripts/Install/InstallDarwin.sh b/Scripts/Install/InstallDarwin.sh
index 4e3011a..4c81fcb 100755
--- a/Scripts/Install/InstallDarwin.sh
+++ b/Scripts/Install/InstallDarwin.sh
@@ -2,19 +2,18 @@
 
 install() {
 
-	sudo xcode-select --install || exit 1
+	sudo xcode-select --install 
 
 	/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" || exit 1
 
-	brew install python git cmake libsodium openssl || exit 1
+	xargs brew install < "${installToolsPath}/PackageListBrew.txt" || exit 1
 
 	sudo pip3 install -r "${installToolsPath}/PackageListPython.txt" || exit 1
-
 }
 
 upgrade() {
 
-	brew upgrade || exit 1
+	xargs brew upgrade < "${installToolsPath}/PackageListBrew.txt" || exit 1
 
 	sudo pip3 install -r "${installToolsPath}/PackageListPython.txt" --upgrade || exit 1
 
@@ -24,9 +23,9 @@ set -o nounset
 
 installToolsPath="$(cd "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P)"
 
-if [ "${1}" = "--upgrade" ]; then
+if [ "${1-}" = "--upgrade" ]; then
 	upgrade
-elif [ -z "${1}" ]; then
+elif [ -z "${1-}" ]; then
 	install
 else
 	echo "error: Invalid argument. Use '--upgrade' switch to upgrade packages, or none to install packages."
diff --git a/Scripts/Install/InstallLinux.sh b/Scripts/Install/InstallLinux.sh
index b710324..1972c40 100755
--- a/Scripts/Install/InstallLinux.sh
+++ b/Scripts/Install/InstallLinux.sh
@@ -22,9 +22,9 @@ set -o nounset
 
 installToolsPath="$(cd "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P)"
 
-if [ "${1}" = "--upgrade" ]; then
+if [ "${1-}" = "--upgrade" ]; then
 	upgrade
-elif [ -z "${1}" ]; then
+elif [ -z "${1-}" ]; then
 	install
 else
 	echo "error: Invalid argument. Use '--upgrade' switch to upgrade packages, or none to install packages."
diff --git a/Scripts/Install/PackageListBrew.txt b/Scripts/Install/PackageListBrew.txt
index 10261cb..91cc448 100644
--- a/Scripts/Install/PackageListBrew.txt
+++ b/Scripts/Install/PackageListBrew.txt
@@ -2,4 +2,4 @@ cmake
 git
 libsodium
 openssl
-python
\ No newline at end of file
+python