diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index aae26b3..5c3fc82 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -16,6 +16,7 @@ jobs:
     strategy:
       matrix:
         php-version:
+          - 7.3
           - 7.4
     steps:
       - name: Checkout
@@ -104,7 +105,7 @@ jobs:
 
   coding-guideline:
     runs-on: ubuntu-latest
-    needs: 
+    needs:
       - check-dependencies
       - xml-linting
     steps:
@@ -176,6 +177,7 @@ jobs:
     strategy:
       matrix:
         php-version:
+          - 7.3
           - 7.4
     steps:
       - uses: actions/checkout@v2
diff --git a/Classes/Controller/Backend/ImportController.php b/Classes/Controller/Backend/ImportController.php
index d8766a8..5c147a4 100644
--- a/Classes/Controller/Backend/ImportController.php
+++ b/Classes/Controller/Backend/ImportController.php
@@ -33,10 +33,25 @@ use WerkraumMedia\ThueCat\View\Backend\Menu;
 
 class ImportController extends AbstractController
 {
-    private Importer $importer;
-    private ImportLogRepository $repository;
-    private TranslationService $translation;
-    private Menu $menu;
+    /**
+     * @var Importer
+     */
+    private $importer;
+
+    /**
+     * @var ImportLogRepository
+     */
+    private $repository;
+
+    /**
+     * @var TranslationService
+     */
+    private $translation;
+
+    /**
+     * @var Menu
+     */
+    private $menu;
 
     public function __construct(
         Importer $importer,
diff --git a/Classes/Controller/Backend/OverviewController.php b/Classes/Controller/Backend/OverviewController.php
index 39d68c8..53c1ba4 100644
--- a/Classes/Controller/Backend/OverviewController.php
+++ b/Classes/Controller/Backend/OverviewController.php
@@ -29,9 +29,20 @@ use WerkraumMedia\ThueCat\View\Backend\Menu;
 
 class OverviewController extends AbstractController
 {
-    private OrganisationRepository $organisationRepository;
-    private ImportConfigurationRepository $importConfigurationRepository;
-    private Menu $menu;
+    /**
+     * @var OrganisationRepository
+     */
+    private $organisationRepository;
+
+    /**
+     * @var ImportConfigurationRepository
+     */
+    private $importConfigurationRepository;
+
+    /**
+     * @var Menu
+     */
+    private $menu;
 
     public function __construct(
         OrganisationRepository $organisationRepository,
diff --git a/Classes/Domain/Import/Converter/Organisation.php b/Classes/Domain/Import/Converter/Organisation.php
index db984c6..c833690 100644
--- a/Classes/Domain/Import/Converter/Organisation.php
+++ b/Classes/Domain/Import/Converter/Organisation.php
@@ -32,8 +32,15 @@ use WerkraumMedia\ThueCat\Domain\Model\Backend\ImportConfiguration;
 
 class Organisation implements Converter
 {
-    private Parser $parser;
-    private LanguageHandling $language;
+    /**
+     * @var Parser
+     */
+    private $parser;
+
+    /**
+     * @var LanguageHandling
+     */
+    private $language;
 
     public function __construct(
         Parser $parser,
diff --git a/Classes/Domain/Import/Converter/Registry.php b/Classes/Domain/Import/Converter/Registry.php
index a9421dd..9c0ac5e 100644
--- a/Classes/Domain/Import/Converter/Registry.php
+++ b/Classes/Domain/Import/Converter/Registry.php
@@ -28,7 +28,10 @@ namespace WerkraumMedia\ThueCat\Domain\Import\Converter;
  */
 class Registry
 {
-    private array $converters = [];
+    /**
+     * @var Converter[]
+     */
+    private $converters = [];
 
     public function registerConverter(Converter $converter): void
     {
diff --git a/Classes/Domain/Import/Converter/TouristAttraction.php b/Classes/Domain/Import/Converter/TouristAttraction.php
index 563b6ac..7ce7465 100644
--- a/Classes/Domain/Import/Converter/TouristAttraction.php
+++ b/Classes/Domain/Import/Converter/TouristAttraction.php
@@ -35,11 +35,30 @@ use WerkraumMedia\ThueCat\Domain\Repository\Backend\TownRepository;
 
 class TouristAttraction implements Converter
 {
-    private Parser $parser;
-    private Offers $parserForOffers;
-    private LanguageHandling $language;
-    private OrganisationRepository $organisationRepository;
-    private TownRepository $townRepository;
+    /**
+     * @var Parser
+     */
+    private $parser;
+
+    /**
+     * @var Offers
+     */
+    private $parserForOffers;
+
+    /**
+     * @var LanguageHandling
+     */
+    private $language;
+
+    /**
+     * @var OrganisationRepository
+     */
+    private $organisationRepository;
+
+    /**
+     * @var TownRepository
+     */
+    private $townRepository;
 
     public function __construct(
         Parser $parser,
diff --git a/Classes/Domain/Import/Converter/TouristInformation.php b/Classes/Domain/Import/Converter/TouristInformation.php
index 3ef90a6..858ad5e 100644
--- a/Classes/Domain/Import/Converter/TouristInformation.php
+++ b/Classes/Domain/Import/Converter/TouristInformation.php
@@ -34,10 +34,25 @@ use WerkraumMedia\ThueCat\Domain\Repository\Backend\TownRepository;
 
 class TouristInformation implements Converter
 {
-    private Parser $parser;
-    private LanguageHandling $language;
-    private OrganisationRepository $organisationRepository;
-    private TownRepository $townRepository;
+    /**
+     * @var Parser
+     */
+    private $parser;
+
+    /**
+     * @var LanguageHandling
+     */
+    private $language;
+
+    /**
+     * @var OrganisationRepository
+     */
+    private $organisationRepository;
+
+    /**
+     * @var TownRepository
+     */
+    private $townRepository;
 
     public function __construct(
         Parser $parser,
diff --git a/Classes/Domain/Import/Converter/Town.php b/Classes/Domain/Import/Converter/Town.php
index 3f351cd..424f780 100644
--- a/Classes/Domain/Import/Converter/Town.php
+++ b/Classes/Domain/Import/Converter/Town.php
@@ -33,9 +33,20 @@ use WerkraumMedia\ThueCat\Domain\Repository\Backend\OrganisationRepository;
 
 class Town implements Converter
 {
-    private Parser $parser;
-    private LanguageHandling $language;
-    private OrganisationRepository $organisationRepository;
+    /**
+     * @var Parser
+     */
+    private $parser;
+
+    /**
+     * @var LanguageHandling
+     */
+    private $language;
+
+    /**
+     * @var OrganisationRepository
+     */
+    private $organisationRepository;
 
     public function __construct(
         Parser $parser,
diff --git a/Classes/Domain/Import/Importer.php b/Classes/Domain/Import/Importer.php
index 8dcc510..eda3aa6 100644
--- a/Classes/Domain/Import/Importer.php
+++ b/Classes/Domain/Import/Importer.php
@@ -36,13 +36,40 @@ use WerkraumMedia\ThueCat\Domain\Repository\Backend\ImportLogRepository;
 
 class Importer
 {
-    private UrlProviderRegistry $urls;
-    private ConverterRegistry $converter;
-    private FetchData $fetchData;
-    private SaveData $saveData;
-    private ImportLog $importLog;
-    private ImportLogRepository $importLogRepository;
-    private ImportConfiguration $configuration;
+    /**
+     * @var UrlProviderRegistry
+     */
+    private $urls;
+
+    /**
+     * @var ConverterRegistry
+     */
+    private $converter;
+
+    /**
+     * @var FetchData
+     */
+    private $fetchData;
+
+    /**
+     * @var SaveData
+     */
+    private $saveData;
+
+    /**
+     * @var ImportLog
+     */
+    private $importLog;
+
+    /**
+     * @var ImportLogRepository
+     */
+    private $importLogRepository;
+
+    /**
+     * @var ImportConfiguration
+     */
+    private $configuration;
 
     public function __construct(
         UrlProviderRegistry $urls,
diff --git a/Classes/Domain/Import/Importer/FetchData.php b/Classes/Domain/Import/Importer/FetchData.php
index 637fe71..35aed36 100644
--- a/Classes/Domain/Import/Importer/FetchData.php
+++ b/Classes/Domain/Import/Importer/FetchData.php
@@ -29,9 +29,20 @@ use TYPO3\CMS\Core\Cache\Frontend\FrontendInterface as CacheFrontendInterface;
 
 class FetchData
 {
-    private RequestFactoryInterface $requestFactory;
-    private ClientInterface $httpClient;
-    private CacheFrontendInterface $cache;
+    /**
+     * @var RequestFactoryInterface
+     */
+    private $requestFactory;
+
+    /**
+     * @var ClientInterface
+     */
+    private $httpClient;
+
+    /**
+     * @var CacheFrontendInterface
+     */
+    private $cache;
 
     public function __construct(
         RequestFactoryInterface $requestFactory,
diff --git a/Classes/Domain/Import/Importer/LanguageHandling.php b/Classes/Domain/Import/Importer/LanguageHandling.php
index 6144be0..781f356 100644
--- a/Classes/Domain/Import/Importer/LanguageHandling.php
+++ b/Classes/Domain/Import/Importer/LanguageHandling.php
@@ -26,7 +26,10 @@ use TYPO3\CMS\Core\Site\SiteFinder;
 
 class LanguageHandling
 {
-    private SiteFinder $siteFinder;
+    /**
+     * @var SiteFinder
+     */
+    private $siteFinder;
 
     public function __construct(
         SiteFinder $siteFinder
diff --git a/Classes/Domain/Import/Importer/SaveData.php b/Classes/Domain/Import/Importer/SaveData.php
index 413a007..12936e7 100644
--- a/Classes/Domain/Import/Importer/SaveData.php
+++ b/Classes/Domain/Import/Importer/SaveData.php
@@ -32,9 +32,20 @@ use WerkraumMedia\ThueCat\Domain\Model\Backend\ImportLogEntry;
 
 class SaveData
 {
-    private DataHandler $dataHandler;
-    private ConnectionPool $connectionPool;
-    private array $errorLog;
+    /**
+     * @var DataHandler
+     */
+    private $dataHandler;
+
+    /**
+     * @var ConnectionPool
+     */
+    private $connectionPool;
+
+    /**
+     * @var mixed[]
+     */
+    private $errorLog;
 
     public function __construct(
         DataHandler $dataHandler,
diff --git a/Classes/Domain/Import/JsonLD/Parser.php b/Classes/Domain/Import/JsonLD/Parser.php
index 88f4997..3d01c27 100644
--- a/Classes/Domain/Import/JsonLD/Parser.php
+++ b/Classes/Domain/Import/JsonLD/Parser.php
@@ -31,10 +31,25 @@ use WerkraumMedia\ThueCat\Domain\Import\JsonLD\Parser\OpeningHours;
 
 class Parser
 {
-    private GenericFields $genericFields;
-    private OpeningHours $openingHours;
-    private Address $address;
-    private Media $media;
+    /**
+     * @var GenericFields
+     */
+    private $genericFields;
+
+    /**
+     * @var OpeningHours
+     */
+    private $openingHours;
+
+    /**
+     * @var Address
+     */
+    private $address;
+
+    /**
+     * @var Media
+     */
+    private $media;
 
     public function __construct(
         GenericFields $genericFields,
diff --git a/Classes/Domain/Import/JsonLD/Parser/Address.php b/Classes/Domain/Import/JsonLD/Parser/Address.php
index b203060..9e18511 100644
--- a/Classes/Domain/Import/JsonLD/Parser/Address.php
+++ b/Classes/Domain/Import/JsonLD/Parser/Address.php
@@ -72,8 +72,8 @@ class Address
     private function getGeo(array $geo): array
     {
         return [
-            'latitude' => floatval($geo['schema:latitude']['@value'] ?? 0.00),
-            'longitude' => floatval($geo['schema:longitude']['@value'] ?? 0.00),
+            'latitude' => floatval($geo['schema:latitude']['@value'] ?? 0.0),
+            'longitude' => floatval($geo['schema:longitude']['@value'] ?? 0.0),
         ];
     }
 }
diff --git a/Classes/Domain/Import/JsonLD/Parser/GenericFields.php b/Classes/Domain/Import/JsonLD/Parser/GenericFields.php
index a3aad2c..a7913c8 100644
--- a/Classes/Domain/Import/JsonLD/Parser/GenericFields.php
+++ b/Classes/Domain/Import/JsonLD/Parser/GenericFields.php
@@ -25,7 +25,10 @@ use TYPO3\CMS\Core\Site\Entity\SiteLanguage;
 
 class GenericFields
 {
-    private LanguageValues $languageValues;
+    /**
+     * @var LanguageValues
+     */
+    private $languageValues;
 
     public function __construct(
         LanguageValues $languageValues
diff --git a/Classes/Domain/Import/JsonLD/Parser/Media.php b/Classes/Domain/Import/JsonLD/Parser/Media.php
index 9b4a7e5..b390da9 100644
--- a/Classes/Domain/Import/JsonLD/Parser/Media.php
+++ b/Classes/Domain/Import/JsonLD/Parser/Media.php
@@ -25,7 +25,10 @@ use WerkraumMedia\ThueCat\Domain\Import\Importer\FetchData;
 
 class Media
 {
-    private FetchData $fetchData;
+    /**
+     * @var FetchData
+     */
+    private $fetchData;
 
     public function __construct(
         FetchData $fetchData
diff --git a/Classes/Domain/Import/JsonLD/Parser/Offers.php b/Classes/Domain/Import/JsonLD/Parser/Offers.php
index de4d94a..369ee2b 100644
--- a/Classes/Domain/Import/JsonLD/Parser/Offers.php
+++ b/Classes/Domain/Import/JsonLD/Parser/Offers.php
@@ -25,7 +25,10 @@ use TYPO3\CMS\Core\Site\Entity\SiteLanguage;
 
 class Offers
 {
-    private GenericFields $genericFields;
+    /**
+     * @var GenericFields
+     */
+    private $genericFields;
 
     public function __construct(
         GenericFields $genericFields
diff --git a/Classes/Domain/Import/Model/EntityCollection.php b/Classes/Domain/Import/Model/EntityCollection.php
index 91b3962..66e44cf 100644
--- a/Classes/Domain/Import/Model/EntityCollection.php
+++ b/Classes/Domain/Import/Model/EntityCollection.php
@@ -28,7 +28,7 @@ class EntityCollection
     /**
      * @var Entity[]
      */
-    private array $entities = [];
+    private $entities = [];
 
     public function add(Entity $entity): void
     {
diff --git a/Classes/Domain/Import/Model/GenericEntity.php b/Classes/Domain/Import/Model/GenericEntity.php
index 76bf6ad..5e51f56 100644
--- a/Classes/Domain/Import/Model/GenericEntity.php
+++ b/Classes/Domain/Import/Model/GenericEntity.php
@@ -25,13 +25,40 @@ namespace WerkraumMedia\ThueCat\Domain\Import\Model;
 
 class GenericEntity implements Entity
 {
-    private int $typo3StoragePid;
-    private string $typo3DatabaseTableName;
-    private int $typo3SystemLanguageUid;
-    private bool $created = false;
-    private int $typo3Uid = 0;
-    private string $remoteId;
-    private array $data;
+    /**
+     * @var int
+     */
+    private $typo3StoragePid;
+
+    /**
+     * @var string
+     */
+    private $typo3DatabaseTableName;
+
+    /**
+     * @var int
+     */
+    private $typo3SystemLanguageUid;
+
+    /**
+     * @var bool
+     */
+    private $created = false;
+
+    /**
+     * @var int
+     */
+    private $typo3Uid = 0;
+
+    /**
+     * @var string
+     */
+    private $remoteId;
+
+    /**
+     * @var mixed[]
+     */
+    private $data;
 
     public function __construct(
         int $typo3StoragePid,
diff --git a/Classes/Domain/Import/UrlProvider/Registry.php b/Classes/Domain/Import/UrlProvider/Registry.php
index 9c892f6..89d7ed9 100644
--- a/Classes/Domain/Import/UrlProvider/Registry.php
+++ b/Classes/Domain/Import/UrlProvider/Registry.php
@@ -30,7 +30,10 @@ use WerkraumMedia\ThueCat\Domain\Model\Backend\ImportConfiguration;
  */
 class Registry
 {
-    private array $provider = [];
+    /**
+     * @var UrlProvider[]
+     */
+    private $provider = [];
 
     public function registerProvider(UrlProvider $provider): void
     {
diff --git a/Classes/Domain/Import/UrlProvider/StaticUrlProvider.php b/Classes/Domain/Import/UrlProvider/StaticUrlProvider.php
index c3577b4..60eb5ae 100644
--- a/Classes/Domain/Import/UrlProvider/StaticUrlProvider.php
+++ b/Classes/Domain/Import/UrlProvider/StaticUrlProvider.php
@@ -28,7 +28,10 @@ use WerkraumMedia\ThueCat\Domain\Model\Backend\ImportConfiguration;
 
 class StaticUrlProvider implements UrlProvider
 {
-    private array $urls = [];
+    /**
+     * @var string[]
+     */
+    private $urls = [];
 
     public function __construct(
         ImportConfiguration $configuration
@@ -46,7 +49,7 @@ class StaticUrlProvider implements UrlProvider
 
     public function createWithConfiguration(
         ImportConfiguration $configuration
-    ): StaticUrlProvider {
+    ): UrlProvider {
         return GeneralUtility::makeInstance(self::class, $configuration);
     }
 
diff --git a/Classes/Domain/Model/Backend/AbstractEntity.php b/Classes/Domain/Model/Backend/AbstractEntity.php
index 9741550..560ee08 100644
--- a/Classes/Domain/Model/Backend/AbstractEntity.php
+++ b/Classes/Domain/Model/Backend/AbstractEntity.php
@@ -27,10 +27,25 @@ use TYPO3\CMS\Extbase\DomainObject\AbstractEntity as Typo3AbstractEntity;
 
 class AbstractEntity extends Typo3AbstractEntity
 {
-    protected string $remoteId = '';
-    protected string $title = '';
-    protected string $description = '';
-    protected ?\DateTimeImmutable $tstamp = null;
+    /**
+     * @var string
+     */
+    protected $remoteId = '';
+
+    /**
+     * @var string
+     */
+    protected $title = '';
+
+    /**
+     * @var string
+     */
+    protected $description = '';
+
+    /**
+     * @var \DateTimeImmutable|null
+     */
+    protected $tstamp = null;
 
     public function getRemoteId(): string
     {
diff --git a/Classes/Domain/Model/Backend/ImportConfiguration.php b/Classes/Domain/Model/Backend/ImportConfiguration.php
index f40e7af..400ab1b 100644
--- a/Classes/Domain/Model/Backend/ImportConfiguration.php
+++ b/Classes/Domain/Model/Backend/ImportConfiguration.php
@@ -29,10 +29,25 @@ use TYPO3\CMS\Extbase\DomainObject\AbstractEntity;
 
 class ImportConfiguration extends AbstractEntity
 {
-    protected string $title = '';
-    protected string $type = '';
-    protected string $configuration = '';
-    protected ?\DateTimeImmutable $tstamp = null;
+    /**
+     * @var string
+     */
+    protected $title = '';
+
+    /**
+     * @var string
+     */
+    protected $type = '';
+
+    /**
+     * @var string
+     */
+    protected $configuration = '';
+
+    /**
+     * @var \DateTimeImmutable|null
+     */
+    protected $tstamp = null;
 
     public function getTitle(): string
     {
diff --git a/Classes/Domain/Model/Backend/ImportLogEntry.php b/Classes/Domain/Model/Backend/ImportLogEntry.php
index 3d550cf..9f52cdf 100644
--- a/Classes/Domain/Model/Backend/ImportLogEntry.php
+++ b/Classes/Domain/Model/Backend/ImportLogEntry.php
@@ -53,7 +53,10 @@ class ImportLogEntry extends Typo3AbstractEntity
      */
     protected $errors = '';
 
-    protected array $errorsAsArray = [];
+    /**
+     * @var string[]
+     */
+    protected $errorsAsArray = [];
 
     public function __construct(
         Entity $entity,
diff --git a/Classes/Domain/Model/Frontend/Address.php b/Classes/Domain/Model/Frontend/Address.php
index f1ecdfc..2248ae6 100644
--- a/Classes/Domain/Model/Frontend/Address.php
+++ b/Classes/Domain/Model/Frontend/Address.php
@@ -27,8 +27,15 @@ use TYPO3\CMS\Core\Type\TypeInterface;
 
 class Address implements TypeInterface
 {
-    private string $serialized;
-    private array $data;
+    /**
+     * @var string
+     */
+    private $serialized;
+
+    /**
+     * @var mixed[]
+     */
+    private $data;
 
     public function __construct(string $serialized)
     {
diff --git a/Classes/Domain/Model/Frontend/Media.php b/Classes/Domain/Model/Frontend/Media.php
index d8be397..deaefdf 100644
--- a/Classes/Domain/Model/Frontend/Media.php
+++ b/Classes/Domain/Model/Frontend/Media.php
@@ -27,8 +27,15 @@ use TYPO3\CMS\Core\Type\TypeInterface;
 
 class Media implements TypeInterface
 {
-    private string $serialized;
-    private array $data;
+    /**
+     * @var string
+     */
+    private $serialized;
+
+    /**
+     * @var mixed[]
+     */
+    private $data;
 
     public function __construct(string $serialized)
     {
diff --git a/Classes/Domain/Model/Frontend/Offer.php b/Classes/Domain/Model/Frontend/Offer.php
index d32599b..22fc5dc 100644
--- a/Classes/Domain/Model/Frontend/Offer.php
+++ b/Classes/Domain/Model/Frontend/Offer.php
@@ -25,9 +25,20 @@ namespace WerkraumMedia\ThueCat\Domain\Model\Frontend;
 
 class Offer
 {
-    private string $title;
-    private string $description;
-    private array $prices;
+    /**
+     * @var string
+     */
+    private $title;
+
+    /**
+     * @var string
+     */
+    private $description;
+
+    /**
+     * @var mixed[]
+     */
+    private $prices;
 
     private function __construct(
         string $title,
@@ -39,7 +50,10 @@ class Offer
         $this->prices = $prices;
     }
 
-    public static function createFromArray(array $rawData): self
+    /**
+     * @return $this
+     */
+    public static function createFromArray(array $rawData)
     {
         $prices = [];
         foreach ($rawData['prices'] as $price) {
diff --git a/Classes/Domain/Model/Frontend/Offers.php b/Classes/Domain/Model/Frontend/Offers.php
index fb6249c..e1e099d 100644
--- a/Classes/Domain/Model/Frontend/Offers.php
+++ b/Classes/Domain/Model/Frontend/Offers.php
@@ -30,9 +30,20 @@ use TYPO3\CMS\Core\Type\TypeInterface;
  */
 class Offers implements TypeInterface, \Iterator
 {
-    private string $serialized = '';
-    private array $array = [];
-    private int $position = 0;
+    /**
+     * @var string
+     */
+    private $serialized = '';
+
+    /**
+     * @var mixed[]
+     */
+    private $array = [];
+
+    /**
+     * @var int
+     */
+    private $position = 0;
 
     public function __construct(string $serialized)
     {
diff --git a/Classes/Domain/Model/Frontend/OpeningHour.php b/Classes/Domain/Model/Frontend/OpeningHour.php
index ecff698..c1e1a83 100644
--- a/Classes/Domain/Model/Frontend/OpeningHour.php
+++ b/Classes/Domain/Model/Frontend/OpeningHour.php
@@ -25,11 +25,30 @@ namespace WerkraumMedia\ThueCat\Domain\Model\Frontend;
 
 class OpeningHour
 {
-    private string $opens;
-    private string $closes;
-    private array $daysOfWeek;
-    private ?\DateTimeImmutable $from;
-    private ?\DateTimeImmutable $through;
+    /**
+     * @var string
+     */
+    private $opens;
+
+    /**
+     * @var string
+     */
+    private $closes;
+
+    /**
+     * @var mixed[]
+     */
+    private $daysOfWeek;
+
+    /**
+     * @var \DateTimeImmutable|null
+     */
+    private $from;
+
+    /**
+     * @var \DateTimeImmutable|null
+     */
+    private $through;
 
     private function __construct(
         string $opens,
@@ -45,7 +64,10 @@ class OpeningHour
         $this->through = $through;
     }
 
-    public static function createFromArray(array $rawData): self
+    /**
+     * @return $this
+     */
+    public static function createFromArray(array $rawData)
     {
         $from = null;
         if (isset($rawData['from'])) {
diff --git a/Classes/Domain/Model/Frontend/OpeningHours.php b/Classes/Domain/Model/Frontend/OpeningHours.php
index a70d476..11ff49d 100644
--- a/Classes/Domain/Model/Frontend/OpeningHours.php
+++ b/Classes/Domain/Model/Frontend/OpeningHours.php
@@ -30,9 +30,20 @@ use TYPO3\CMS\Core\Type\TypeInterface;
  */
 class OpeningHours implements TypeInterface, \Iterator
 {
-    private string $serialized = '';
-    private array $array = [];
-    private int $position = 0;
+    /**
+     * @var string
+     */
+    private $serialized = '';
+
+    /**
+     * @var mixed[]
+     */
+    private $array = [];
+
+    /**
+     * @var int
+     */
+    private $position = 0;
 
     public function __construct(string $serialized)
     {
diff --git a/Classes/Domain/Model/Frontend/Price.php b/Classes/Domain/Model/Frontend/Price.php
index 77276ea..0a1ab7f 100644
--- a/Classes/Domain/Model/Frontend/Price.php
+++ b/Classes/Domain/Model/Frontend/Price.php
@@ -25,11 +25,30 @@ namespace WerkraumMedia\ThueCat\Domain\Model\Frontend;
 
 class Price
 {
-    private string $title;
-    private string $description;
-    private float $price;
-    private string $currency;
-    private string $rule;
+    /**
+     * @var string
+     */
+    private $title;
+
+    /**
+     * @var string
+     */
+    private $description;
+
+    /**
+     * @var float
+     */
+    private $price;
+
+    /**
+     * @var string
+     */
+    private $currency;
+
+    /**
+     * @var string
+     */
+    private $rule;
 
     private function __construct(
         string $title,
@@ -45,7 +64,10 @@ class Price
         $this->rule = $rule;
     }
 
-    public static function createFromArray(array $rawData): self
+    /**
+     * @return $this
+     */
+    public static function createFromArray(array $rawData)
     {
         return new self(
             $rawData['title'],
diff --git a/Classes/Domain/Model/Frontend/TouristAttraction.php b/Classes/Domain/Model/Frontend/TouristAttraction.php
index f07e0d8..6cedb8d 100644
--- a/Classes/Domain/Model/Frontend/TouristAttraction.php
+++ b/Classes/Domain/Model/Frontend/TouristAttraction.php
@@ -27,13 +27,40 @@ use TYPO3\CMS\Extbase\DomainObject\AbstractEntity;
 
 class TouristAttraction extends AbstractEntity
 {
-    protected string $title = '';
-    protected string $description = '';
-    protected ?OpeningHours $openingHours = null;
-    protected ?Offers $offers = null;
-    protected ?Address $address = null;
-    protected ?Town $town = null;
-    protected ?Media $media = null;
+    /**
+     * @var string
+     */
+    protected $title = '';
+
+    /**
+     * @var string
+     */
+    protected $description = '';
+
+    /**
+     * @var OpeningHours|null
+     */
+    protected $openingHours = null;
+
+    /**
+     * @var Offers|null
+     */
+    protected $offers = null;
+
+    /**
+     * @var Address|null
+     */
+    protected $address = null;
+
+    /**
+     * @var Town|null
+     */
+    protected $town = null;
+
+    /**
+     * @var Media|null
+     */
+    protected $media = null;
 
     public function getTitle(): string
     {
diff --git a/Classes/Domain/Model/Frontend/Town.php b/Classes/Domain/Model/Frontend/Town.php
index 4bdd44e..67854d4 100644
--- a/Classes/Domain/Model/Frontend/Town.php
+++ b/Classes/Domain/Model/Frontend/Town.php
@@ -27,8 +27,15 @@ use TYPO3\CMS\Extbase\DomainObject\AbstractEntity;
 
 class Town extends AbstractEntity
 {
-    protected string $title = '';
-    protected string $description = '';
+    /**
+     * @var string
+     */
+    protected $title = '';
+
+    /**
+     * @var string
+     */
+    protected $description = '';
 
     public function getTitle(): string
     {
diff --git a/Classes/Domain/Repository/Backend/ImportLogRepository.php b/Classes/Domain/Repository/Backend/ImportLogRepository.php
index 75db46c..f738072 100644
--- a/Classes/Domain/Repository/Backend/ImportLogRepository.php
+++ b/Classes/Domain/Repository/Backend/ImportLogRepository.php
@@ -32,7 +32,10 @@ use WerkraumMedia\ThueCat\Domain\Model\Backend\ImportLog;
 
 class ImportLogRepository extends Repository
 {
-    private DataHandler $dataHandler;
+    /**
+     * @var DataHandler
+     */
+    private $dataHandler;
 
     public function __construct(
         ObjectManagerInterface $objectManager,
diff --git a/Classes/Frontend/DataProcessing/ResolveEntities.php b/Classes/Frontend/DataProcessing/ResolveEntities.php
index a058a36..62acca1 100644
--- a/Classes/Frontend/DataProcessing/ResolveEntities.php
+++ b/Classes/Frontend/DataProcessing/ResolveEntities.php
@@ -33,9 +33,20 @@ use TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController;
 
 class ResolveEntities implements DataProcessorInterface
 {
-    private ConnectionPool $connectionPool;
-    private DataMapper $dataMapper;
-    private TypoScriptFrontendController $tsfe;
+    /**
+     * @var ConnectionPool
+     */
+    private $connectionPool;
+
+    /**
+     * @var DataMapper
+     */
+    private $dataMapper;
+
+    /**
+     * @var TypoScriptFrontendController
+     */
+    private $tsfe;
 
     public function __construct(
         ConnectionPool $connectionPool,
diff --git a/Classes/View/Backend/Menu.php b/Classes/View/Backend/Menu.php
index 6478446..f5e172b 100644
--- a/Classes/View/Backend/Menu.php
+++ b/Classes/View/Backend/Menu.php
@@ -32,7 +32,10 @@ use WerkraumMedia\ThueCat\Typo3Wrapper\TranslationService;
 
 class Menu
 {
-    private TranslationService $translation;
+    /**
+     * @var TranslationService
+     */
+    private $translation;
 
     public function __construct(
         TranslationService $translation
diff --git a/composer.json b/composer.json
index d22fb10..6066263 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
         }
     },
     "require": {
-        "php": "^7.4",
+        "php": "^7.3",
         "ext-json": "*",
         "psr/http-client": "^1.0",
         "psr/http-factory": "^1.0",
diff --git a/ecs.php b/ecs.php
index 169ee16..1dcf8c8 100644
--- a/ecs.php
+++ b/ecs.php
@@ -5,6 +5,7 @@ declare(strict_types=1);
 use PhpCsFixer\Fixer\ArrayNotation\ArraySyntaxFixer;
 use PhpCsFixer\Fixer\ArrayNotation\NoMultilineWhitespaceAroundDoubleArrowFixer;
 use PhpCsFixer\Fixer\ArrayNotation\TrailingCommaInMultilineArrayFixer;
+use PhpCsFixer\Fixer\ClassNotation\ClassAttributesSeparationFixer;
 use PhpCsFixer\Fixer\Import\FullyQualifiedStrictTypesFixer;
 use PhpCsFixer\Fixer\Import\NoUnusedImportsFixer;
 use PhpCsFixer\Fixer\PhpUnit\PhpUnitTestAnnotationFixer;
@@ -50,4 +51,11 @@ return static function (ContainerConfigurator $containerConfigurator): void {
     $services->set(PhpUnitTestAnnotationFixer::class)->call('configure', [[
         'style' => 'annotation',
     ]]);
+    $services->set(ClassAttributesSeparationFixer::class)->call('configure', [[
+        'elements' => [
+            'const' => ClassAttributesSeparationFixer::SPACING_ONE,
+            'method' => ClassAttributesSeparationFixer::SPACING_ONE,
+            'property' => ClassAttributesSeparationFixer::SPACING_ONE,
+        ],
+    ]]);
 };