diff --git a/app/libs/util/wechat.rb b/app/libs/util/wechat.rb
index 069322f18..1b064ba94 100644
--- a/app/libs/util/wechat.rb
+++ b/app/libs/util/wechat.rb
@@ -7,7 +7,8 @@ module Util::Wechat
     attr_accessor :appid, :secret
 
     def js_sdk_signature(url, noncestr, timestamp)
-      str = { jsapi_ticket: jsapi_ticket, noncestr: noncestr, timestamp: timestamp, url: url }.to_query
+      data = { jsapi_ticket: jsapi_ticket, noncestr: noncestr, timestamp: timestamp, url: url }
+      str = data.map { |k, v| "#{k}=#{v}" }.join('&')
       Digest::SHA1.hexdigest(str)
     end