diff --git a/hwe/j_diplomacy_respond_letter.php b/hwe/j_diplomacy_respond_letter.php
index c1b69c73..a8e492c7 100644
--- a/hwe/j_diplomacy_respond_letter.php
+++ b/hwe/j_diplomacy_respond_letter.php
@@ -80,8 +80,8 @@ if($isAgree){
     while($prevLetterNo !== null){
         $db->update('ng_diplomacy', [
             'state'=>'replaced',
-        ], 'no=%i', $letter['prev_no']);
-        $prevLetterNo = $db->queryFirstField('SELECT prev_no FROM ng_diplomacy WHERE state != \'replaced\' AND no = %i', $prevLetterNo);
+        ], 'no=%i', $prevLetterNo);
+        $prevLetterNo = $db->queryFirstField('SELECT prev_no FROM ng_diplomacy WHERE state != \'cancelled\' AND no = %i', $prevLetterNo);
     }
     $msgText = "외교 서신 #{$letterNo}가 승인되었습니다.";
 }