diff --git a/lib/private/Log/ExceptionSerializer.php b/lib/private/Log/ExceptionSerializer.php
index 8cfdb57b22..fe28120b39 100644
--- a/lib/private/Log/ExceptionSerializer.php
+++ b/lib/private/Log/ExceptionSerializer.php
@@ -92,8 +92,10 @@ class ExceptionSerializer {
 	];
 
 	private function editTrace(array &$sensitiveValues, array $traceLine): array {
-		$sensitiveValues = array_merge($sensitiveValues, $traceLine['args']);
-		$traceLine['args'] = ['*** sensitive parameters replaced ***'];
+		if (isset($traceLine['args'])) {
+			$sensitiveValues = array_merge($sensitiveValues, $traceLine['args']);
+			$traceLine['args'] = ['*** sensitive parameters replaced ***'];
+		}
 		return $traceLine;
 	}