diff --git a/common/HttpClient.php b/common/HttpClient.php
index e856e90..a6a0ba5 100644
--- a/common/HttpClient.php
+++ b/common/HttpClient.php
@@ -353,6 +353,9 @@ class HttpClient
 			$client->get($url . '?' . $data);
 		} else if (strtolower($this->method) == self::PUT) {
 			$client->setMethod('put');
+			$client->setHeaders([
+				'Content-Type' => 'application/json'
+			]);
 			if (!is_string($data)) {
 				$data = json_encode($data, JSON_UNESCAPED_UNICODE);
 			}