diff --git a/src/ReCaptcha/RequestMethod/Curl.php b/src/ReCaptcha/RequestMethod/Curl.php
index 2d3b389..19fb812 100644
--- a/src/ReCaptcha/RequestMethod/Curl.php
+++ b/src/ReCaptcha/RequestMethod/Curl.php
@@ -76,6 +76,8 @@ public function exec($ch)
      */
     public function close($ch)
     {
-        curl_close($ch);
+        if (PHP_MAJOR_VERSION < 8) {
+            curl_close($ch);
+        }
     }
 }