diff --git a/src/scripts/darwin.sh b/src/scripts/darwin.sh
index 3f57d7af..37e35dbc 100644
--- a/src/scripts/darwin.sh
+++ b/src/scripts/darwin.sh
@@ -18,7 +18,7 @@ add_log() {
 
 # Function to remove extensions
 remove_extension() {
-  extension=$1
+  local extension=$1
   sudo sed -Ei '' "/=(.*\/)?\"?$extension/d" "$ini_file"
   sudo rm -rf "$scan_dir"/*"$extension"* >/dev/null 2>&1
   sudo rm -rf "$ext_dir"/"$extension".so >/dev/null 2>&1
@@ -26,7 +26,7 @@ remove_extension() {
 
 # Function to test if extension is loaded
 check_extension() {
-  extension=$1
+  local extension=$1
   if [ "$extension" != "mysql" ]; then
     php -m | grep -i -q -w "$extension"
   else
@@ -42,7 +42,7 @@ pecl_install() {
 
 # Function to get the PECL version
 get_pecl_version() {
-  extension=$1
+  local extension=$1
   stability="$(echo "$2" | grep -m 1 -Eio "(alpha|beta|rc|snapshot|preview)")"
   pecl_rest='https://pecl.php.net/rest/r/'
   response=$(curl "${curl_opts[@]}" "$pecl_rest$extension"/allreleases.xml)
@@ -55,7 +55,7 @@ get_pecl_version() {
 
 # Function to install a PECL version
 add_pecl_extension() {
-  extension=$1
+  local extension=$1
   pecl_version=$2
   prefix=$3
   if [[ $pecl_version =~ .*(alpha|beta|rc|snapshot|preview).* ]]; then
@@ -114,7 +114,7 @@ add_brew_extension() {
 
 # Function to setup extensions
 add_extension() {
-  extension=$1
+  local extension=$1
   install_command=$2
   prefix=$3
   if ! check_extension "$extension" && [ -e "$ext_dir/$extension.so" ]; then
@@ -132,7 +132,7 @@ add_extension() {
 
 # Function to pre-release extensions using PECL
 add_unstable_extension() {
-  extension=$1
+  local extension=$1
   stability=$2
   prefix=$3
   pecl_version=$(get_pecl_version "$extension" "$stability")
diff --git a/src/scripts/ext/phalcon.sh b/src/scripts/ext/phalcon.sh
index dd0c8749..1a1d9963 100644
--- a/src/scripts/ext/phalcon.sh
+++ b/src/scripts/ext/phalcon.sh
@@ -20,7 +20,7 @@ update_ppa() {
 
 # Function to install phalcon
 install_phalcon() {
-  extension=$1
+  local extension=$1
   version=$2
   (update_ppa && sudo DEBIAN_FRONTEND=noninteractive apt-get install -y "php$version-psr" "php$version-$extension" >/dev/null 2>&1 && add_log "$tick" "$extension" "Installed and enabled") ||
   add_log "$cross" "$extension" "Could not install $extension on PHP $semver"
diff --git a/src/scripts/linux.sh b/src/scripts/linux.sh
index b63874b0..82f33e6d 100644
--- a/src/scripts/linux.sh
+++ b/src/scripts/linux.sh
@@ -62,7 +62,7 @@ configure_pecl() {
 
 # Function to get the PECL version
 get_pecl_version() {
-  extension=$1
+  local extension=$1
   stability="$(echo "$2" | grep -m 1 -Eio "(alpha|beta|rc|snapshot|preview)")"
   pecl_rest='https://pecl.php.net/rest/r/'
   response=$(curl "${curl_opts[@]}" "$pecl_rest$extension"/allreleases.xml)
@@ -89,7 +89,7 @@ enable_extension() {
 
 # Function to test if extension is loaded
 check_extension() {
-  extension=$1
+  local extension=$1
   if [ "$extension" != "mysql" ]; then
     php -m | grep -i -q -w "$extension"
   else
@@ -99,7 +99,7 @@ check_extension() {
 
 # Function to delete extensions
 delete_extension() {
-  extension=$1
+  local extension=$1
   sudo sed -Ei "/=(.*\/)?\"?$extension/d" "$ini_file"
   sudo sed -Ei "/=(.*\/)?\"?$extension/d" "$pecl_file"
   sudo rm -rf "$scan_dir"/*"$extension"* >/dev/null 2>&1
@@ -109,7 +109,7 @@ delete_extension() {
 
 # Function to disable and delete extensions
 remove_extension() {
-  extension=$1
+  local extension=$1
   if [ -e /etc/php/"$version"/mods-available/"$extension".ini ]; then
     sudo phpdismod -v "$version" "$extension"
   fi
@@ -118,7 +118,7 @@ remove_extension() {
 
 # Function to setup extensions
 add_extension() {
-  extension=$1
+  local extension=$1
   install_command=$2
   prefix=$3
   enable_extension "$extension" "$prefix"
@@ -135,7 +135,7 @@ add_extension() {
 
 # Function to install a PECL version
 add_pecl_extension() {
-  extension=$1
+  local extension=$1
   pecl_version=$2
   prefix=$3
   configure_pecl
@@ -158,7 +158,7 @@ add_pecl_extension() {
 
 # Function to pre-release extensions using PECL
 add_unstable_extension() {
-  extension=$1
+  local extension=$1
   stability=$2
   prefix=$3
   pecl_version=$(get_pecl_version "$extension" "$stability")