diff --git a/head.php b/head.php
index 72e14e0e0..f13f15271 100644
--- a/head.php
+++ b/head.php
@@ -127,7 +127,9 @@ if (G5_IS_MOBILE) {
                     <?php
                     $sql2 = " select * from {$g5['board_table']} where gr_id = '{$row['gr_id']}' and bo_show_menu = '1' and bo_device <> 'mobile' order by bo_order ";
                     $result2 = sql_query($sql2);
-                    for ($bi=0; $row2=sql_fetch_array($result2); $bi++) { // bi 는 board index
+                    $gnb_zindex = 999; // gnb_1dli z-index 값 설정용
+                    for ($gi=0; $row=sql_fetch_array($result); $gi++) { // gi 는 group index
+                        $gnb_zindex -= 1; // html 구조에서 앞선 gnb_1dli 에 더 높은 z-index 값 부여
                      ?>
                     <li class="gnb_2dli"><a href="<?php echo G5_BBS_URL ?>/board.php?bo_table=<?php echo $row2['bo_table'] ?>" class="gnb_2da"><?php echo $row2['bo_subject'] ?></a></li>
                     <?php } ?>