diff --git a/src/OaiPmh/OaiSet/AbstractOaiSet.php b/src/OaiPmh/OaiSet/AbstractOaiSet.php
index 3d9b3a805caa0a967d2aae4a3767898e6ef981d8..f755690b78ba9f99f535723537b7be5d41708c95 100644
--- a/src/OaiPmh/OaiSet/AbstractOaiSet.php
+++ b/src/OaiPmh/OaiSet/AbstractOaiSet.php
@@ -256,7 +256,7 @@ abstract class AbstractOaiSet extends AbstractXmlGenerator implements OaiSetInte
             return;
         }
         $set = null;
-        if ((integer) $setSpec) {
+        if ((int) $setSpec) {
             try {
                 $set = $this->api->read('item_sets', ['id' => $setSpec])->getContent();
             } catch (\Omeka\Api\Exception\NotFoundException $e) {