diff --git a/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php b/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php
index 357c893d5b..aeeb3a32da 100644
--- a/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php
+++ b/lib/Froxlor/Cron/Http/LetsEncrypt/AcmeSh.php
@@ -491,7 +491,7 @@ private static function checkFsFilesAreNewer($domain, $cert_date = 0)
 
 		if (is_dir($certificate_folder) && file_exists($ssl_file) && is_readable($ssl_file)) {
 			$cert_data = openssl_x509_parse(file_get_contents($ssl_file));
-			if (strtotime($cert_data['validTo_time_t']) > strtotime($cert_date)) {
+			if ($cert_data['validTo_time_t'] > strtotime($cert_date)) {
 				return true;
 			}
 		}