diff --git a/common.php b/common.php
index cc0d8879a..e642cfa11 100644
--- a/common.php
+++ b/common.php
@@ -95,6 +95,7 @@ if (file_exists($dbconfig_file)) {
     $connect_db = sql_connect(G5_MYSQL_HOST, G5_MYSQL_USER, G5_MYSQL_PASSWORD) or die('MySQL Connect Error!!!');
     $select_db  = sql_select_db(G5_MYSQL_DB, $connect_db) or die('MySQL DB Error!!!');
     @mysql_query(" set names utf8 ");
+    if(defined('G5_MYSQL_SET_MODE') && G5_MYSQL_SET_MODE) @mysql_query("SET SESSION sql_mode = ''");
     if (defined(G5_TIMEZONE)) @mysql_query(" set time_zone = '".G5_TIMEZONE."'");
 } else {
 ?>
diff --git a/install/install_db.php b/install/install_db.php
index c10009d41..e4cfe29f0 100644
--- a/install/install_db.php
+++ b/install/install_db.php
@@ -23,7 +23,6 @@ $admin_pass  = $_POST['admin_pass'];
 $admin_name  = $_POST['admin_name'];
 $admin_email = $_POST['admin_email'];
 
-@mysql_query('set names utf8');
 $dblink = @mysql_connect($mysql_host, $mysql_user, $mysql_pass);
 if (!$dblink) {
     echo '<meta http-equiv="content-type" content="text/html; charset=utf-8">'.PHP_EOL;
@@ -32,7 +31,6 @@ if (!$dblink) {
     exit;
 }
 
-@mysql_query('set names utf8');
 $select_db = @mysql_select_db($mysql_db, $dblink);
 if (!$select_db) {
     echo '<meta http-equiv="content-type" content="text/html; charset=utf-8">'.PHP_EOL;
@@ -40,6 +38,13 @@ if (!$select_db) {
     echo '<div><a href="./install_config.php">뒤로가기</a></div>'.PHP_EOL;
     exit;
 }
+
+$mysql_set_mode = 'false';
+@mysql_query('set names utf8');
+if(version_compare(mysql_get_server_info(), '5.6.6', '>=')  == 1) {
+    @mysql_query("SET SESSION sql_mode = ''");
+    $mysql_set_mode = 'true';
+}
 ?>
 
 <h2><?php echo G5_VERSION ?> 설치가 시작되었습니다.</h2>
@@ -186,7 +191,8 @@ fwrite($f, "if (!defined('_GNUBOARD_')) exit;\n");
 fwrite($f, "define('G5_MYSQL_HOST', '{$mysql_host}');\n");
 fwrite($f, "define('G5_MYSQL_USER', '{$mysql_user}');\n");
 fwrite($f, "define('G5_MYSQL_PASSWORD', '{$mysql_pass}');\n");
-fwrite($f, "define('G5_MYSQL_DB', '{$mysql_db}');\n\n");
+fwrite($f, "define('G5_MYSQL_DB', '{$mysql_db}');\n");
+fwrite($f, "define('G5_MYSQL_SET_MODE', {$mysql_set_mode});\n\n");
 fwrite($f, "define('G5_TABLE_PREFIX', '{$table_prefix}');\n\n");
 fwrite($f, "\$g5['write_prefix'] = G5_TABLE_PREFIX.'write_'; // 게시판 테이블명 접두사\n\n");
 fwrite($f, "\$g5['auth_table'] = G5_TABLE_PREFIX.'auth'; // 관리권한 설정 테이블\n");