diff --git a/src/BMailApi.php b/src/BMailApi.php
index 51519dd..1ef534b 100644
--- a/src/BMailApi.php
+++ b/src/BMailApi.php
@@ -33,7 +33,10 @@ class BMailApi
         try {
              return $client->request('post', $url, [
                 'form_params' => $template,
-                'headers' => ['Authorization' => 'Bearer ' . $this->api_key]
+                'headers' => [
+                    'Authorization' => 'Bearer ' . $this->api_key,
+                    'Accept' => 'application/json'
+                ]
             ])->getBody();
 
         } catch(\Exception $e) {