diff --git a/qywechat.class.php b/qywechat.class.php
index 76c71832..28d6d546 100644
--- a/qywechat.class.php
+++ b/qywechat.class.php
@@ -890,7 +890,7 @@ public function checkAuth($appid='',$appsecret='',$token=''){
 		if ($result)
 		{
 			$json = json_decode($result,true);
-			if (!$json || isset($json['errcode'])) {
+			if (!$json || $json['errcode']) {
 				$this->errCode = $json['errcode'];
 				$this->errMsg = $json['errmsg'];
 				return false;