diff --git a/src/Recaptcha.php b/src/Recaptcha.php
index 25d3d32..f84ff60 100644
--- a/src/Recaptcha.php
+++ b/src/Recaptcha.php
@@ -84,6 +84,6 @@ private function getIp(ServerRequestInterface $request): string
             return $request->getAttribute($this->ipAttribute);
         }
 
-        return isset($server['REMOTE_ADDR']) ? $server['REMOTE_ADDR'] : '';
+        return $server['REMOTE_ADDR'] ?? '';
     }
 }