diff --git a/bbs/gcaptcha/gcaptcha.lib.php b/bbs/gcaptcha/gcaptcha.lib.php
index a1b9af3a2..4f9bf841b 100644
--- a/bbs/gcaptcha/gcaptcha.lib.php
+++ b/bbs/gcaptcha/gcaptcha.lib.php
@@ -172,6 +172,7 @@ function captcha_html($class='captcha')
     $obj = new gcaptcha();
     $obj->run();
 
+    $rand = rand();
     $jpg_file_url = G4_DATA_URL.'/cache/'.$obj->captcha_filename.'.jpg';
     $wav_file_url = G4_DATA_URL.'/cache/'.$obj->captcha_filename.'.wav';
 
@@ -179,8 +180,8 @@ function captcha_html($class='captcha')
     $html .= PHP_EOL.'<script src="'.G4_GCAPTCHA_URL.'/gcaptcha.js"></script>'; 
     $html .= '<fieldset id="captcha" class="'.$class.'">';
     $html .= '<legend class="sound_only">자동등록방지</legend>';
-    $html .= '<img src="'.$jpg_file_url.'?_='.rand().'" alt="자동등록방지 숫자">';
-    $html .= '<a href="'.$wav_file_url.'" id="captcha_wav" target="_blank"><img src="'.G4_GCAPTCHA_URL.'/img/sound.gif" alt="숫자를 음성으로 듣기"></a>';
+    $html .= '<img src="'.$jpg_file_url.'?_='.$rand.'" alt="자동등록방지 숫자">';
+    $html .= '<a href="'.$wav_file_url.'?_='.$rand.'" id="captcha_wav" target="_blank"><img src="'.G4_GCAPTCHA_URL.'/img/sound.gif" alt="숫자를 음성으로 듣기"></a>';
     $html .= '<input type="text" id="captcha_key" name="captcha_key" class="captcha_box frm_input" size="6" maxlength="6" required title="자동등록방지 숫자 입력">';
     $html .= '<p class="sound_only">자동등록방지 숫자를 순서대로 입력하세요.</p>';
     $html .= '</fieldset>';
diff --git a/bbs/gcaptcha/wav.php b/bbs/gcaptcha/wav.php
deleted file mode 100644
index f45405a9e..000000000
--- a/bbs/gcaptcha/wav.php
+++ /dev/null
@@ -1,74 +0,0 @@
-<?php
-include_once("./_common.php");
-
-// prepare an array of wavfiles
-$wavs_dir = $g4['path'].'/plugin/captcha/wavs/';
-$number = (string)$_SESSION['ss_captcha_key'];
-$wavs = array();
-for($i=0;$i<strlen($number);$i++){
-    $file = $wavs_dir.$number[$i].'.wav';
-    $wavs[] = $file;
-}
-
-header('Content-type: audio/x-wav');
-header('Content-Disposition: attachment;filename=captcha.wav');
-
-echo joinwavs($wavs);
-
-
-/**
- * Join multiple wav files
- *
- * All wave files need to have the same format and need to be uncompressed.
- * The headers of the last file will be used (with recalculated datasize
- * of course)
- *
- * @link http://ccrma.stanford.edu/CCRMA/Courses/422/projects/WaveFormat/
- * @link http://www.thescripts.com/forum/thread3770.html
- */
-function joinwavs($wavs)
-{
-    $fields = join('/',array( 'H8ChunkID', 'VChunkSize', 'H8Format',
-                              'H8Subchunk1ID', 'VSubchunk1Size',
-                              'vAudioFormat', 'vNumChannels', 'VSampleRate',
-                              'VByteRate', 'vBlockAlign', 'vBitsPerSample' ));
-    $data = '';
-    $info = array();
-    foreach($wavs as $wav){
-        $fp     = fopen($wav,'rb');
-        $header = fread($fp,36);
-        $info   = unpack($fields,$header);
-
-        // read optional extra stuff
-        if($info['Subchunk1Size'] > 16){
-            $header .= fread($fp,($info['Subchunk1Size']-16));
-        }
-
-        // read SubChunk2ID
-        $header .= fread($fp,4);
-
-        // read Subchunk2Size
-        $size  = unpack('vsize',fread($fp, 4));
-        $size  = $size['size'];
-
-        // read data
-        $data .= fread($fp,$size);
-    }
-
-    return ''
-        .pack('a4', 'RIFF')
-        .pack('V', strlen($data) + 36)
-        .pack('a4', 'WAVE')
-        .pack('a4', 'fmt ')
-        .pack('V', $info['Subchunk1Size'])  // 16
-        .pack('v', $info['AudioFormat'])    // 1
-        .pack('v', $info['NumChannels'])    // 1
-        .pack('V', $info['SampleRate'])     // 8000
-        .pack('V', $info['ByteRate'])       // 8000
-        .pack('v', $info['BlockAlign'])     // 1
-        .pack('v', $info['BitsPerSample'])  // 8
-        .pack('a4', 'data')
-        .pack('V', strlen($data))
-        .$data;
-}
-?>