diff --git a/module/VuFind/src/VuFind/RecordDriver/SolrMarc.php b/module/VuFind/src/VuFind/RecordDriver/SolrMarc.php
index ae8fbd08280513bcfb7521d7ad844be0a4fca280..bc54a57ec40e60306ae254c7c28820877e519155 100644
--- a/module/VuFind/src/VuFind/RecordDriver/SolrMarc.php
+++ b/module/VuFind/src/VuFind/RecordDriver/SolrMarc.php
@@ -1055,7 +1055,7 @@ class SolrMarc extends SolrDefault
     {
         if ($this->hasILS()) {
             $biblioLevel = strtolower($this->getBibliographicLevel());
-            if ("monograph" == $biblioLevel || strstr("part", $biblioLevel)) {
+            if ("monograph" == $biblioLevel || strstr($biblioLevel, "part")) {
                 if ($this->ils->getTitleHoldsMode() != "disabled") {
                     return $this->titleHoldLogic->getHold($this->getUniqueID());
                 }