diff --git a/wchat/common/HttpClient.php b/wchat/common/HttpClient.php
index 891255b..8972fcc 100644
--- a/wchat/common/HttpClient.php
+++ b/wchat/common/HttpClient.php
@@ -213,7 +213,7 @@ class HttpClient
 	 */
 	public function setHeader($key, $value)
 	{
-		$this->header[$key] = $value;
+		$this->header[strtoupper($key)] = $value;
 	}
 
 	/**
@@ -222,7 +222,7 @@ class HttpClient
 	 */
 	public function addHeader($key, $value)
 	{
-		$this->header[$key] = $value;
+		$this->header[strtoupper($key)] = $value;
 	}
 
 	/**
@@ -513,7 +513,6 @@ class HttpClient
 		}
 
 		if (!empty($this->_data)) {
-			var_dump($this->_data);
 			$client->setData($this->_data);
 		}
 		$client->execute($url);
@@ -554,7 +553,12 @@ class HttpClient
 				return $data;
 			}
 		}
-		$contentType = $this->header['Content-Type'] ?? 'application/x-www-form-urlencoded';
+
+		$contentType = 'application/x-www-form-urlencoded';
+		if (isset($this->header['CONTENT-TYPE'])) {
+			$contentType = $this->header['CONTENT-TYPE'];
+		}
+
 		if (strpos($contentType, 'json') !== false) {
 			return Help::toJson($data);
 		} else if (strpos($contentType, 'xml') !== false) {
@@ -941,7 +945,7 @@ class HttpClient
 			return [];
 		}
 		foreach ($headers as $key => $val) {
-			$this->header[$key] = $val;
+			$this->header[strtoupper($key)] = $val;
 		}
 		return $this->header;
 	}