diff --git a/module/VuFindSearch/src/VuFindSearch/Backend/AbstractBackend.php b/module/VuFindSearch/src/VuFindSearch/Backend/AbstractBackend.php
index eaa8841fa2b..bee16ac7f84 100644
--- a/module/VuFindSearch/src/VuFindSearch/Backend/AbstractBackend.php
+++ b/module/VuFindSearch/src/VuFindSearch/Backend/AbstractBackend.php
@@ -34,6 +34,7 @@
 use VuFindSearch\Response\RecordCollectionFactoryInterface;
 use VuFindSearch\Response\RecordCollectionInterface;
 
+use function count;
 use function sprintf;
 
 /**
diff --git a/module/VuFindSearch/src/VuFindSearch/Response/RecordTrait.php b/module/VuFindSearch/src/VuFindSearch/Response/RecordTrait.php
index 274fe9fbe93..c4ad4110cb6 100644
--- a/module/VuFindSearch/src/VuFindSearch/Response/RecordTrait.php
+++ b/module/VuFindSearch/src/VuFindSearch/Response/RecordTrait.php
@@ -55,7 +55,7 @@ trait RecordTrait
      *
      * @var string|null
      */
-    protected $resultSetIdentifier;
+    protected $resultSetIdentifier = null;
 
     /**
      * Used for identifying the search backend used to find the record