diff --git a/wchat/common/HttpClient.php b/wchat/common/HttpClient.php
index c859d4c..5563ebe 100644
--- a/wchat/common/HttpClient.php
+++ b/wchat/common/HttpClient.php
@@ -560,7 +560,7 @@ class HttpClient
 		} else if (strpos($contentType, 'xml') !== false) {
 			return Help::toXml($data);
 		} else {
-			return Help::toJson($data);
+			return http_build_query($data);
 		}
 	}