diff --git a/shadowsocks-libev.sh b/shadowsocks-libev.sh
index 7b221b5..6c61daa 100644
--- a/shadowsocks-libev.sh
+++ b/shadowsocks-libev.sh
@@ -311,13 +311,17 @@ pre_install(){
     echo "Press any key to start...or press Ctrl+C to cancel"
     char=`get_char`
     #Install necessary dependencies
-    echo -e "[${green}Info${plain}] Adding the EPEL repository..."
-    [ ! -f /etc/yum.repos.d/epel.repo ] && yum install -y epel-release
-    [ ! "$(command -v yum-config-manager)" ] && yum install -y yum-utils
-    [ ! -f /etc/yum.repos.d/epel.repo ] && echo -e "${red}Error${plain} Install EPEL repository failed, please check it." && exit 1
-    [ -f /etc/yum.repos.d/epel.repo ] && yum-config-manager --enable epel
-    echo -e "[${green}Info${plain}] Adding the EPEL repository complete..."
-    yum install -y unzip openssl openssl-devel gettext gcc autoconf libtool automake make asciidoc xmlto udns-devel libev-devel pcre pcre-devel git c-ares-devel
+    echo -e "[${green}Info${plain}] Checking the EPEL repository..."
+    if [ ! -f /etc/yum.repos.d/epel.repo ]; then
+        yum install -y -q epel-release
+    fi
+    [ ! -f /etc/yum.repos.d/epel.repo ] && echo -e "[${red}Error${plain}] Install EPEL repository failed, please check it." && exit 1
+    [ ! "$(command -v yum-config-manager)" ] && yum install -y -q yum-utils
+    if [ x"`yum-config-manager epel | grep -w enabled | awk '{print $3}'`" != x"True" ]; then
+        yum-config-manager --enable epel
+    fi
+    echo -e "[${green}Info${plain}] Checking the EPEL repository complete..."
+    yum install -y -q unzip openssl openssl-devel gettext gcc autoconf libtool automake make asciidoc xmlto libev-devel pcre pcre-devel git c-ares-devel
 }
 
 download() {