diff --git a/ShadowsocksX-NG/install_helper.sh b/ShadowsocksX-NG/install_helper.sh
index c27a00e..e7ac8db 100755
--- a/ShadowsocksX-NG/install_helper.sh
+++ b/ShadowsocksX-NG/install_helper.sh
@@ -5,7 +5,8 @@
 #
 #  Created by clowwindy on 14-3-15.
 
-cd `dirname "${BASH_SOURCE[0]}"`
+cd "$(dirname "${BASH_SOURCE[0]}")"
+
 sudo mkdir -p "/Library/Application Support/ShadowsocksX-NG/"
 sudo cp proxy_conf_helper "/Library/Application Support/ShadowsocksX-NG/"
 sudo chown root:admin "/Library/Application Support/ShadowsocksX-NG/proxy_conf_helper"
diff --git a/ShadowsocksX-NG/install_privoxy.sh b/ShadowsocksX-NG/install_privoxy.sh
index a89d9e8..dc9d4b8 100755
--- a/ShadowsocksX-NG/install_privoxy.sh
+++ b/ShadowsocksX-NG/install_privoxy.sh
@@ -7,7 +7,8 @@
 #  Copyright © 2016年 zhfish. All rights reserved.
 
 
-cd `dirname "${BASH_SOURCE[0]}"`
+cd "$(dirname "${BASH_SOURCE[0]}")"
+
 privoxyVersion=3.0.26.static
 mkdir -p "$HOME/Library/Application Support/ShadowsocksX-NG/privoxy-$privoxyVersion"
 cp -f privoxy "$HOME/Library/Application Support/ShadowsocksX-NG/privoxy-$privoxyVersion/"
diff --git a/ShadowsocksX-NG/install_ss_local.sh b/ShadowsocksX-NG/install_ss_local.sh
index e1275cc..477ba90 100755
--- a/ShadowsocksX-NG/install_ss_local.sh
+++ b/ShadowsocksX-NG/install_ss_local.sh
@@ -7,7 +7,7 @@
 #  Copyright © 2016年 qiuyuzhou. All rights reserved.
 
 
-cd `dirname "${BASH_SOURCE[0]}"`
+cd "$(dirname "${BASH_SOURCE[0]}")"
 
 NGDir="$HOME/Library/Application Support/ShadowsocksX-NG"
 TargetDir="$NGDir/ss-local-3.2.5"
diff --git a/ShadowsocksX-NG/kcptun/install_kcptun.sh b/ShadowsocksX-NG/kcptun/install_kcptun.sh
index 5f43fa5..f42f322 100644
--- a/ShadowsocksX-NG/kcptun/install_kcptun.sh
+++ b/ShadowsocksX-NG/kcptun/install_kcptun.sh
@@ -10,7 +10,7 @@
 
 VERSION="v20170718"
 
-cd `dirname "${BASH_SOURCE[0]}"`
+cd "$(dirname "${BASH_SOURCE[0]}")"
 
 mkdir -p "$HOME/Library/Application Support/ShadowsocksX-NG/kcptun_$VERSION"
 cp -f kcptun_client "$HOME/Library/Application Support/ShadowsocksX-NG/kcptun_$VERSION/"
diff --git a/ShadowsocksX-NG/v2ray-plugin/install_v2ray_plugin.sh b/ShadowsocksX-NG/v2ray-plugin/install_v2ray_plugin.sh
index 2f2667b..fe43146 100644
--- a/ShadowsocksX-NG/v2ray-plugin/install_v2ray_plugin.sh
+++ b/ShadowsocksX-NG/v2ray-plugin/install_v2ray_plugin.sh
@@ -9,7 +9,7 @@
 
 VERSION="1.1.0"
 
-cd `dirname "${BASH_SOURCE[0]}"`
+cd "$(dirname "${BASH_SOURCE[0]}")"
 
 mkdir -p "$HOME/Library/Application Support/ShadowsocksX-NG/v2ray-plugin_$VERSION"
 cp -f v2ray-plugin "$HOME/Library/Application Support/ShadowsocksX-NG/v2ray-plugin_$VERSION/"