diff --git a/lib/internal/Magento/Framework/HTTP/ClientInterface.php b/lib/internal/Magento/Framework/HTTP/ClientInterface.php
index 643f298ef4c45..e2e4a89af8fba 100644
--- a/lib/internal/Magento/Framework/HTTP/ClientInterface.php
+++ b/lib/internal/Magento/Framework/HTTP/ClientInterface.php
@@ -99,7 +99,7 @@ public function get($uri);
      * Make POST request
      *
      * @param string $uri full uri
-     * @param array $params POST fields array
+     * @param array|string $params POST fields array or string in case of JSON or XML data
      * @return void
      */
     public function post($uri, $params);