diff --git a/install_nginx.sh b/install_nginx.sh
index 70bbe75..b84dbac 100644
--- a/install_nginx.sh
+++ b/install_nginx.sh
@@ -57,7 +57,7 @@ target_openssl_ver="1.1.1w"
 if [ "$(readlink -f `which openssl`)" == "/opt/openssl/bin/openssl" ]; then
     openssl_dir="/opt/openssl/ssl"
     openssl_source_dir="/root/openssl-$target_openssl_ver"
-    if [ -z `sudo readlink -f "$openssl_source_dir"` ]; then
+    if [ ! -e "$openssl_source_dir" ] || [ -z `readlink -f "$openssl_source_dir"` ]; then
         force_reinstall_openssl="1"
     else
         if [ -d /opt/openssl/ssl/certs ] && [ ! -L /opt/openssl/ssl/certs ]; then
@@ -254,6 +254,7 @@ if [[ $(vercomp "$nginx_ver" "$nginx_target_ver") ==  "<" ]] || [[ "$1" == '--fo
     fi
     if [[ $nginx_conf_exist == "0" ]]; then
         nginx_conf_path="/etc/nginx/nginx.conf"
+        sudo cp -f /etc/nginx/nginx.conf /etc/nginx/nginx_bak.conf
         server_block_start=`sudo grep  -E '^\s*server\s*{' $nginx_conf_path -n|cut -d : -f 1`
         http_block_start=`sudo grep  -E '^\s*http\s*{' $nginx_conf_path -n|cut -d : -f 1`
         http_block_end_offset=`cat $nginx_conf_path | awk '{if (NR>='$http_block_start') print}'|grep  -E '^}' -n|cut -d : -f 1|xargs|awk '{print $1}'`