diff --git a/weixin.py b/weixin.py
index ea1172c..0cf69c3 100755
--- a/weixin.py
+++ b/weixin.py
@@ -101,7 +101,7 @@ class WebWeixin(object):
 		return False
 
 	def genQRCode(self):
-		if sys.platform.find('win') >= 0:
+		if sys.platform.startswith('win'):
 			self._showQRCodeImg()
 		else:
 			self._str2qr('https://login.weixin.qq.com/l/' + self.uuid)