diff --git a/Adapter/TaxonCategoryAdapter.php b/Adapter/TaxonCategoryAdapter.php
index 6aab188..ec10fc0 100644
--- a/Adapter/TaxonCategoryAdapter.php
+++ b/Adapter/TaxonCategoryAdapter.php
@@ -13,6 +13,7 @@
 
 namespace Sulu\Bundle\SyliusConsumerBundle\Adapter;
 
+use Doctrine\ORM\EntityManagerInterface;
 use Sulu\Bundle\CategoryBundle\Entity\CategoryInterface;
 use Sulu\Bundle\CategoryBundle\Entity\CategoryRepositoryInterface;
 use Sulu\Bundle\CategoryBundle\Entity\CategoryTranslationInterface;
@@ -38,19 +39,30 @@ class TaxonCategoryAdapter implements TaxonAdapterInterface
      */
     private $categoryTranslationRepository;
 
+    /**
+     * @var EntityManagerInterface
+     */
+    private $entityManager;
+
     public function __construct(
         TaxonCategoryBridgeRepositoryInterface $taxonCategoryBridgeRepository,
         CategoryRepositoryInterface $categoryRepository,
-        CategoryTranslationRepositoryInterface $categoryTranslationRepository
+        CategoryTranslationRepositoryInterface $categoryTranslationRepository,
+        EntityManagerInterface $entityManager
     ) {
         $this->taxonCategoryBridgeRepository = $taxonCategoryBridgeRepository;
         $this->categoryRepository = $categoryRepository;
         $this->categoryTranslationRepository = $categoryTranslationRepository;
+        $this->entityManager = $entityManager;
     }
 
     public function synchronize(TaxonPayload $payload): void
     {
         $this->handlePayload($payload);
+
+        // Needed to use categories in other adapters
+        // (e.g. category pages with a smart-content filtered by the sylius category)
+        $this->entityManager->flush();
     }
 
     private function handlePayload(TaxonPayload $payload, ?CategoryInterface $parent = null): void
diff --git a/Payload/ProductPayload.php b/Payload/ProductPayload.php
index acef621..98de92c 100644
--- a/Payload/ProductPayload.php
+++ b/Payload/ProductPayload.php
@@ -44,9 +44,9 @@ public function isEnabled(): bool
         return $this->payload->getBoolValue('enabled');
     }
 
-    public function getMainTaxonId(): int
+    public function getMainTaxonId(): ?int
     {
-        return $this->payload->getIntValue('mainTaxonId');
+        return $this->payload->getNullableIntValue('mainTaxonId');
     }
 
     /**
diff --git a/Resources/config/taxon_category_adapter.xml b/Resources/config/taxon_category_adapter.xml
index dfdc81e..fbd44b6 100644
--- a/Resources/config/taxon_category_adapter.xml
+++ b/Resources/config/taxon_category_adapter.xml
@@ -9,6 +9,7 @@
             <argument type="service" id="sulu.repository.taxon_category_bridge"/>
             <argument type="service" id="sulu.repository.category"/>
             <argument type="service" id="sulu.repository.category_translation"/>
+            <argument type="service" id="doctrine.orm.entity_manager"/>
 
             <tag name="sulu_sylius_consumer.adapter.taxon"/>
         </service>
diff --git a/Tests/Application/config/config.yml b/Tests/Application/config/config.yml
index bbdb349..dd256d3 100644
--- a/Tests/Application/config/config.yml
+++ b/Tests/Application/config/config.yml
@@ -2,14 +2,6 @@
 doctrine:
     dbal:
         url: '%env(resolve:DATABASE_URL)%'
-    orm:
-        mappings:
-            gedmo_tree:
-                type: xml
-                prefix: Gedmo\Tree\Entity
-                dir: "%kernel.project_dir%/../../vendor/gedmo/doctrine-extensions/lib/Gedmo/Tree/Entity"
-                alias: GedmoTree
-                is_bundle: false
 
 framework:
     router:
diff --git a/Tests/Functional/Adapter/TaxonCategoryAdapterTest.php b/Tests/Functional/Adapter/TaxonCategoryAdapterTest.php
index f19e088..aecc166 100644
--- a/Tests/Functional/Adapter/TaxonCategoryAdapterTest.php
+++ b/Tests/Functional/Adapter/TaxonCategoryAdapterTest.php
@@ -38,7 +38,9 @@ public function testSynchronize(): void
         $taxonPayload = new TaxonPayload(1, MockSyliusData::TAXON);
 
         $adapter->synchronize($taxonPayload);
-        $this->getEntityManager()->flush();
+
+        // Adapter flushed the entity-manager - by clearing it we can check if that works correctly
+        $this->getEntityManager()->clear();
 
         $bridge1 = $this->getEntityManager()->find(TaxonCategoryBridge::class, 1);
         $bridge2 = $this->getEntityManager()->find(TaxonCategoryBridge::class, 2);