diff --git a/src/Flysystem/Adapter/FedoraAdapter.php b/src/Flysystem/Adapter/FedoraAdapter.php
index 6ee588b5..fd5d8453 100644
--- a/src/Flysystem/Adapter/FedoraAdapter.php
+++ b/src/Flysystem/Adapter/FedoraAdapter.php
@@ -152,7 +152,7 @@ class FedoraAdapter implements AdapterInterface {
     }
     // phpcs:enable
     foreach ($links as $link) {
-      if ($link['rel'] == 'type' && $link[0] == '<http://www.w3.org/ns/ldp#NonRDFSource>') {
+      if (isset($link['rel']) && $link['rel'] == 'type' && $link[0] == '<http://www.w3.org/ns/ldp#NonRDFSource>') {
         $type = 'file';
         break;
       }