diff --git a/code/AuditFactory.php b/code/AuditFactory.php
index ebd4015..7c47508 100644
--- a/code/AuditFactory.php
+++ b/code/AuditFactory.php
@@ -7,6 +7,7 @@
 use Monolog\Handler\SyslogHandler;
 use Monolog\Logger;
 use Monolog\Processor\WebProcessor;
+use Psr\Log\LoggerInterface;
 use SilverStripe\Core\Injector\Factory;
 
 /**
@@ -15,7 +16,7 @@
  */
 class AuditFactory implements Factory
 {
-    public function create($service, array $params = [])
+    public function create(string $service, array $params = []): LoggerInterface
     {
         if (!empty($params)) {
             throw new Exception('AuditFactory does not support passing params.');