diff --git a/common/HttpClient.php b/common/HttpClient.php
index efc0255..0feb21f 100644
--- a/common/HttpClient.php
+++ b/common/HttpClient.php
@@ -416,7 +416,11 @@ class HttpClient
 				curl_setopt($ch, CURLOPT_POST, 1);
 			}
 			if ($this->method != self::GET) {
-				curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
+				if (!empty($this->_data)) {
+					curl_setopt($ch, CURLOPT_POSTFIELDS, $this->_data);
+				} else {
+					curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
+				}
 			}
 
 			curl_setopt($ch, CURLOPT_CUSTOMREQUEST, strtoupper($this->method));