diff --git a/lib/ExceptionSerializer.php b/lib/ExceptionSerializer.php
index 374d1fe..18b3d03 100644
--- a/lib/ExceptionSerializer.php
+++ b/lib/ExceptionSerializer.php
@@ -82,7 +82,7 @@ private function filterTrace(array $trace) {
 			return $traceLine;
 		}, $trace);
 		return array_map(function (array $traceLine) use ($sensitiveValues) {
-			$traceLine['args'] = $this->removeValuesFromArgs($traceLine['args'], $sensitiveValues);
+			$traceLine['args'] = $this->removeValuesFromArgs($traceLine['args'] ?? [], $sensitiveValues);
 			return $traceLine;
 		}, $trace);
 	}
@@ -101,7 +101,7 @@ private function removeValuesFromArgs($args, $values) {
 	private function encodeTrace($trace) {
 		$filteredTrace = $this->filterTrace($trace);
 		return array_map(function (array $line) {
-			$line['args'] = array_map([$this, 'encodeArg'], $line['args']);
+			$line['args'] = array_map([$this, 'encodeArg'], $line['args'] ?? []);
 			return $line;
 		}, $filteredTrace);
 	}