diff --git a/bbs/gcaptcha/down.php b/bbs/gcaptcha/down.php
index 7bb655d24..b7057153e 100644
--- a/bbs/gcaptcha/down.php
+++ b/bbs/gcaptcha/down.php
@@ -2,8 +2,7 @@
 include_once('./_common.php');
 
 $file = addslashes($_GET['file']);
-$captcha_path = mk_subdir($g4['cache_captcha_dir']);
-$filepath = $captcha_path.'/'.$file;
+$filepath = $g4['cache_captcha_path'].'/'.$file;
 $original = "number.wav";
 
 if(preg_match("/msie/i", $_SERVER['HTTP_USER_AGENT']) && preg_match("/5\.5/", $_SERVER['HTTP_USER_AGENT'])) {
diff --git a/bbs/gcaptcha/gcaptcha.lib.php b/bbs/gcaptcha/gcaptcha.lib.php
index 8b33aa866..ef7ae2813 100644
--- a/bbs/gcaptcha/gcaptcha.lib.php
+++ b/bbs/gcaptcha/gcaptcha.lib.php
@@ -246,8 +246,6 @@ function join_wavs($wavs)
 function captcha_file($extension='.png')
 {
     global $g4;
-    mk_subdir($g4['cache_dir']);
-    $captcha_path = mk_subdir($g4['cache_captcha_dir']);
-    return $captcha_path.'/'.abs_ip2long().'_'.$_COOKIE['PHPSESSID'].$extension;
+    return $g4['cache_captcha_path'].'/'.abs_ip2long().'_'.$_COOKIE['PHPSESSID'].$extension;
 }
 ?>
diff --git a/lib/common.lib.php b/lib/common.lib.php
index 659c8e4e3..e894a7d4e 100644
--- a/lib/common.lib.php
+++ b/lib/common.lib.php
@@ -1620,18 +1620,6 @@ function is_checked($field)
 }
 
 
-function mk_subdir($subdir)
-{
-    global $g4;
-    $data_subpath = $g4['path_path'].'/'.$subdir;
-    if (!is_dir($data_subpath)) {
-        @mkdir($data_subpath, 0707);
-        @chmod($data_subpath, 0707);
-    }
-    return $data_subpath;
-}
-
-
 function abs_ip2long($ip='')
 {
     $ip = $ip ? $ip : $_SERVER['REMOTE_ADDR'];