diff --git a/src/Model/Response/AbstractResponse.php b/src/Model/Response/AbstractResponse.php
index c1584c2..2813254 100644
--- a/src/Model/Response/AbstractResponse.php
+++ b/src/Model/Response/AbstractResponse.php
@@ -76,12 +76,10 @@ abstract class AbstractResponse
 
     /**
      * AbstractResponse constructor. Sets response.
-     *
-     * @param \SimpleXmlElement $response
      */
-    public function __construct(\SimpleXmlElement $response = null)
+    public function __construct($response = null)
     {
-        if ($response !== null) {
+        if ($response !== null && $response instanceof \SimpleXmlElement) {
             $this->setResponse($response);
 
             $this->setStatusCode((string) $this->getResponse()->head->processing->status->attributes()->code);
diff --git a/src/Service/CommunicationService.php b/src/Service/CommunicationService.php
index b345e19..8f317d3 100644
--- a/src/Service/CommunicationService.php
+++ b/src/Service/CommunicationService.php
@@ -90,8 +90,10 @@ public function send($xml, $connectionTimeout = 0, $executionTimeout = 0, $retri
 
         $statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
 
-        // close connection
-        curl_close($ch);
+        if (version_compare(PHP_VERSION, '8.0.0', '<')) { // curl_close does nothing since 8.0 and is deprecated since 8.5
+            // close connection
+            curl_close($ch);
+        }
 
         // status codes 3xx and 5xx are not processable by the SDK (we assume that the body will be invalid too)
         $invalidStatusCode = $statusCode < 200 || ($statusCode >= 300 && ($statusCode < 400 || $statusCode >= 500));