diff --git a/module/VuFind/src/VuFind/Hierarchy/TreeDataSource/Solr.php b/module/VuFind/src/VuFind/Hierarchy/TreeDataSource/Solr.php
index 3d6a01ca566598918bfe91f8fb16a36444407eb5..ce9bccc7bac334fe8cc2b89b56054f4c71f664b7 100644
--- a/module/VuFind/src/VuFind/Hierarchy/TreeDataSource/Solr.php
+++ b/module/VuFind/src/VuFind/Hierarchy/TreeDataSource/Solr.php
@@ -120,7 +120,7 @@ class Solr extends AbstractBase
      *
      * @param string $parentID The starting point for the current recursion
      * (equivlent to Solr field hierarchy_parent_id)
-     * @param string $count    The total count of items in the tree
+     * @param string &$count   The total count of items in the tree
      * before this recursion
      *
      * @return string
diff --git a/module/VuFind/src/VuFind/Hierarchy/TreeRenderer/AbstractBase.php b/module/VuFind/src/VuFind/Hierarchy/TreeRenderer/AbstractBase.php
index 0a6e502716883a3bf09fbe8a1bd08f56d2d50ac9..4cc44dd40634a1015974ea559474896552bb5b9c 100644
--- a/module/VuFind/src/VuFind/Hierarchy/TreeRenderer/AbstractBase.php
+++ b/module/VuFind/src/VuFind/Hierarchy/TreeRenderer/AbstractBase.php
@@ -96,7 +96,9 @@ abstract class AbstractBase
             $hierarchyDriver = $this->getRecordDriver()
                 ->tryMethod('getHierarchyDriver');
             if (!is_object($hierarchyDriver)) {
-                throw new \Exception('Cannot load hierarchy driver from record driver.');
+                throw new \Exception(
+                    'Cannot load hierarchy driver from record driver.'
+                );
             }
             $this->dataSource = $hierarchyDriver->getTreeSource();
         }