diff --git a/Model/Category/Repository.php b/Model/Category/Repository.php
index ec22a9b3e..21cc14309 100644
--- a/Model/Category/Repository.php
+++ b/Model/Category/Repository.php
@@ -37,6 +37,7 @@
 namespace Nosto\Tagging\Model\Category;
 
 use Magento\Catalog\Api\Data\CategoryInterface;
+use Magento\Catalog\Model\Category;
 use Magento\Catalog\Model\CategoryRepository;
 use Magento\Catalog\Model\ResourceModel\Category\Collection as CategoryCollection;
 use Magento\Framework\Api\SearchCriteriaBuilder;
@@ -84,7 +85,6 @@ public function getByIds(array $ids)
         //@TODO implement
     }
 
-
     /**
      * @param Store $store
      * @param array $categoryIds
@@ -110,15 +110,13 @@ public function getCategoryCollectionQuery(Store $store, array $categoryIds = []
         return $categories;
     }
 
-
     /**
      * Gets the parent category ID's for a given category
      *
-     * @param CategoryInterface $category
      * @return string[]|null
      * @throws ParentCategoryDisabledException
      */
-    public function resolveParentCategoryIds(CategoryInterface $category)
+    public function resolveParentCategoryIds(Category $category): ?array
     {
         if ($this->getParentIdsFromCache($category)) {
             return $this->getParentIdsFromCache($category);
@@ -135,14 +133,13 @@ public function resolveParentCategoryIds(CategoryInterface $category)
 
         $parentCategoryIds = null;
         if ($category->getLevel() >= 1) {
-            //@TODO: get parents from root category, check if this works
             $parentCategoryIds = $category->getParentIds();
             $this->saveParentIdsToCache($category, $parentCategoryIds);
         }
+
         return $parentCategoryIds;
     }
 
-
     /**
      * Get parent ids from cache. Return null if the cache is not available
      *
diff --git a/Model/ResourceModel/Magento/Category/Collection.php b/Model/ResourceModel/Magento/Category/Collection.php
index d3b3dac93..44703b881 100644
--- a/Model/ResourceModel/Magento/Category/Collection.php
+++ b/Model/ResourceModel/Magento/Category/Collection.php
@@ -36,27 +36,27 @@
 
 namespace Nosto\Tagging\Model\ResourceModel\Magento\Category;
 
-//use Magento\Catalog\Model\Category\Attribute\Source\Status;
 use Magento\Catalog\Model\ResourceModel\Category\Collection as MagentoCategoryCollection;
+use Magento\Framework\Exception\LocalizedException;
 
 class Collection extends MagentoCategoryCollection
 {
     /**
      * @return Collection
+     * @throws LocalizedException
      */
-    public function addActiveFilter()
+    public function addActiveFilter(): Collection
     {
-        // @TODO: Here should be included in the menu
         return $this->addAttributeToFilter('status', ['eq' => 1]);
     }
 
     /**
      * @param array $ids
      * @return Collection
+     * @throws LocalizedException
      */
-    public function addIdsToFilter(array $ids)
+    public function addIdsToFilter(array $ids): Collection
     {
-
         return $this->addAttributeToFilter($this->getIdFieldName(), ['in' => $ids]);
     }
 }
diff --git a/Model/Service/Update/CategoryUpdateService.php b/Model/Service/Update/CategoryUpdateService.php
index 7f9fa4e8a..aeac25f20 100644
--- a/Model/Service/Update/CategoryUpdateService.php
+++ b/Model/Service/Update/CategoryUpdateService.php
@@ -38,6 +38,7 @@
 
 use Exception;
 use Magento\Catalog\Api\Data\CategoryInterface;
+use Magento\Catalog\Model\Category;
 use Magento\Store\Model\Store;
 use Nosto\NostoException;
 use Nosto\Tagging\Exception\ParentCategoryDisabledException;
@@ -124,7 +125,7 @@ public function addCollectionToUpdateMessageQueue(CategoryCollection $collection
     private function toParentCategoryIds(CategoryCollection $collection): array
     {
         $categoryIds = [];
-        /** @var CategoryInterface $category */
+        /** @var Category $category */
         foreach ($collection->getItems() as $category) {
             try {
                 $parents = $this->nostoCategoryRepository->resolveParentCategoryIds($category);