diff --git a/core/Service/Auth/OidcHttpGateway.php b/core/Service/Auth/OidcHttpGateway.php
index 2c77ff8..7ba5908 100644
--- a/core/Service/Auth/OidcHttpGateway.php
+++ b/core/Service/Auth/OidcHttpGateway.php
@@ -47,6 +47,7 @@ class OidcHttpGateway
         $body = @file_get_contents($url, false, $ctx);
         $status = 0;
         $responseHeaders = [];
+        $http_response_header = http_get_last_response_headers() ?? [];
         if ($http_response_header !== []) {
             foreach ($http_response_header as $i => $line) {
                 if ($i === 0 && preg_match('/HTTP\/[\d.]+ (\d+)/', $line, $m)) {