diff --git a/lib/Payplug/Core/HttpClient.php b/lib/Payplug/Core/HttpClient.php
index eef9100..ed52589 100644
--- a/lib/Payplug/Core/HttpClient.php
+++ b/lib/Payplug/Core/HttpClient.php
@@ -253,7 +253,7 @@ private function request(
         }
         elseif (is_array($data) && isset($data['params'])) {
             $headers = array(
-                'Content-Type: Content-Type: application/x-www-form-urlencoded',
+                'Content-Type: application/x-www-form-urlencoded',
             );
         } else {
             $headers = array(