diff --git a/webapp/controller/KefuController.class.php b/webapp/controller/KefuController.class.php
index 140fb40..5533b8c 100644
--- a/webapp/controller/KefuController.class.php
+++ b/webapp/controller/KefuController.class.php
@@ -250,7 +250,7 @@ class KefuController {
         $share_conf = require('../config/kefu.share.config.php');
         while (true) {
             $rows = $conn->execQuery('SELECT idx, accountid, openid, awardtime, gameid ' .
-                                     "FROM accounts WHERE idx > :last_idx LIMIT 0, 1000;",
+                                     ' FROM accounts WHERE idx > :last_idx LIMIT 0, 1000;',
                                      array(
                                          ':last_idx' => $last_idx,
                                      ));
@@ -303,7 +303,7 @@ class KefuController {
         }
         $conn = $this->getMysql($accountid);
         $row = $conn->execQueryOne('SELECT awardtime ' .
-                                   "FROM accounts WHERE accountid = :accountid;",
+                                   ' FROM accounts WHERE accountid = :accountid;',
                                    array(
                                        ':accountid' => $accountid,
                                    ));
@@ -325,9 +325,9 @@ class KefuController {
             return;
         }
         if ($this->sendAwardMail($accountid, $awardConfig)) {
-            $ret = $conn->execScript("UPDATE accounts SET " .
+            $ret = $conn->execScript('UPDATE accounts SET ' .
                                      ' awardtime=:awardtime ' .
-                                     'WHERE accountid=:accountid; ',
+                                     ' WHERE accountid=:accountid; ',
                                      array(
                                          ':accountid' => $accountid,
                                          ':awardtime' => time()