diff --git a/lib/cloudflare.lib.php b/cloudflare.check.php
similarity index 93%
rename from lib/cloudflare.lib.php
rename to cloudflare.check.php
index 2615ab7c5..a78967bb7 100644
--- a/lib/cloudflare.lib.php
+++ b/cloudflare.check.php
@@ -1,8 +1,6 @@
 <?php
-if (!defined('_GNUBOARD_')) exit;
-
 // CloudFlare를 사용시, 사용자 환경에 맞는 $_SERVER['REMOTE_ADDR']과 $_SERVER['HTTPS'] 사용 여부를 수정합니다.
-class G5CheckCloudFlare {
+class G5CloudflareRequestHandler {
     public static function check_cloudflare_ips($user_ip){
         
         // 클라우드플레어 IP, https://www.cloudflare.com/ips
@@ -100,7 +98,7 @@ class G5CheckCloudFlare {
     }
 
 }
-if ($_SERVER['HTTP_CF_CONNECTING_IP'] && G5CheckCloudFlare::check_cloudflare_ips($_SERVER['REMOTE_ADDR'])) {
+if ($_SERVER['HTTP_CF_CONNECTING_IP'] && G5CloudflareRequestHandler::check_cloudflare_ips($_SERVER['REMOTE_ADDR'])) {
     $_SERVER['REMOTE_ADDR'] = preg_replace('/[^0-9a-fA-F:.]/', '', $_SERVER['HTTP_CF_CONNECTING_IP']);
     
     // Cloudflare 환경을 고려한 https 사용여부
diff --git a/common.php b/common.php
index c589e7e8d..9569d16a6 100644
--- a/common.php
+++ b/common.php
@@ -29,6 +29,10 @@ for ($i=0; $i<$ext_cnt; $i++) {
 }
 //==========================================================================================================================
 
+// Cloudflare 사용시 REMOTE_ADDR 에 사용자 IP 적용과 https 사용 여부
+if (isset($_SERVER['HTTP_CF_CONNECTING_IP'])) {
+    include_once('cloudflare.check.php');    // cloudflare 의 ip 대역인지 체크
+}
 
 function g5_path()
 {
diff --git a/config.php b/config.php
index fbc53d046..b636b0338 100644
--- a/config.php
+++ b/config.php
@@ -234,10 +234,5 @@ define('G5_VISIT_BROWSCAP_USE', false);
 */
 define('G5_IP_DISPLAY', '\\1.♡.\\3.\\4');
 
-// Cloudflare 사용시 REMOTE_ADDR 에 사용자 IP 적용과 https 사용 여부
-if (isset($_SERVER['HTTP_CF_CONNECTING_IP'])) {
-    include_once(G5_LIB_PATH.'/cloudflare.lib.php');    // cloudflare 의 ip 대역인지 체크
-}
-
 // KAKAO 우편번호 서비스 CDN
 define('G5_POSTCODE_JS', '<script src="//t1.daumcdn.net/mapjsapi/bundle/postcode/prod/postcode.v2.js" async></script>');
diff --git a/install/ajax.install.check.php b/install/ajax.install.check.php
index 11d8a6264..0730994f7 100644
--- a/install/ajax.install.check.php
+++ b/install/ajax.install.check.php
@@ -1,5 +1,6 @@
 <?php
 $g5_path['path'] = '..';
+include_once('install_common.php');
 include_once('../config.php');
 include_once('./install.function.php');    // 인스톨 과정 함수 모음
 include_once('../lib/common.lib.php');    // 공통 라이브러리
diff --git a/install/index.php b/install/index.php
index 27ded035f..c2d6721e9 100644
--- a/install/index.php
+++ b/install/index.php
@@ -2,6 +2,7 @@
 @header('Content-Type: text/html; charset=utf-8');
 @header('X-Robots-Tag: noindex');
 $g5_path['path'] = '..';
+include_once('install_common.php');
 include_once ('../config.php');
 $title = G5_VERSION." 라이센스 확인 1/3";
 include_once ('./install.inc.php');
diff --git a/install/install_common.php b/install/install_common.php
new file mode 100644
index 000000000..29002dfd4
--- /dev/null
+++ b/install/install_common.php
@@ -0,0 +1,4 @@
+<?php
+if (isset($_SERVER['HTTP_CF_CONNECTING_IP'])) {
+    include_once('../cloudflare.check.php');    // cloudflare 의 ip 대역인지 체크
+}
\ No newline at end of file
diff --git a/install/install_config.php b/install/install_config.php
index 64f54c3f8..06cfb601f 100644
--- a/install/install_config.php
+++ b/install/install_config.php
@@ -9,6 +9,7 @@ header('Pragma: no-cache'); // HTTP/1.0
 @header('X-Robots-Tag: noindex');
 
 $g5_path['path'] = '..';
+include_once('install_common.php');
 include_once ('../config.php');
 $title = G5_VERSION." 초기환경설정 2/3";
 include_once ('./install.inc.php');
diff --git a/install/install_db.php b/install/install_db.php
index 9ff07cef0..f2cba5b4c 100644
--- a/install/install_db.php
+++ b/install/install_db.php
@@ -10,6 +10,7 @@ header('Pragma: no-cache'); // HTTP/1.0
 @header('X-Robots-Tag: noindex');
 
 $g5_path['path'] = '..';
+include_once('install_common.php');
 include_once('../config.php');
 include_once('../lib/common.lib.php');
 include_once('./install.function.php');    // 인스톨 과정 함수 모음