diff --git a/lib/Service/SerialNumberService.php b/lib/Service/SerialNumberService.php
index 71351af472..1bfed76a82 100644
--- a/lib/Service/SerialNumberService.php
+++ b/lib/Service/SerialNumberService.php
@@ -40,7 +40,7 @@ public function generateUniqueSerial(
 			try {
 				$this->crlMapper->createCertificate(
 					$serialString,
-					$certificateOwner ?? 'Unknown',
+					$certificateOwner,
 					$engineName,
 					$instanceId,
 					$generation,