diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index e76475b..b494d8d 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -1,6 +1,13 @@
 parameters:
 	ignoreErrors:
 		-
-			message: "#^Throwing checked exception InvalidArgumentException in yielding method is denied as it gets thrown upon Generator iteration$#"
+			message: '#^Call to an undefined method object\:\:getId\(\)\.$#'
+			identifier: method.notFound
+			count: 1
+			path: src/Serializer/LogSerializer.php
+
+		-
+			message: '#^Throwing checked exception InvalidArgumentException in yielding method is denied as it gets thrown upon Generator iteration$#'
+			identifier: shipmonk.checkedExceptionInYieldingMethod
 			count: 2
 			path: tests/Serializer/LogSerializerTest.php
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 381c1b2..c65ef82 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -1,5 +1,4 @@
 parameters:
-    level: 5
     paths:
         - src/
         - tests/
diff --git a/src/Entity/Log.php b/src/Entity/Log.php
index df4d3a8..cb46968 100755
--- a/src/Entity/Log.php
+++ b/src/Entity/Log.php
@@ -23,7 +23,7 @@ public function __construct(
     ) {
         $this->entityClass = $entity::class;
         $this->entityColumn = $entityColumn;
-        $this->entityOldValue = mb_substr($entityOldValue, 0, Log::MAX_STRING_LENGTH);
+        $this->entityOldValue = $entityOldValue !== null ? mb_substr($entityOldValue, 0, Log::MAX_STRING_LENGTH) : null;
         $this->requestTrace = $requestTrace;
         $this->createdAt = new DateTimeImmutable();
     }
diff --git a/src/Exception/UnsupportObjectException.php b/src/Exception/UnsupportObjectException.php
index 2c472f5..257a254 100644
--- a/src/Exception/UnsupportObjectException.php
+++ b/src/Exception/UnsupportObjectException.php
@@ -6,7 +6,7 @@
 
 class UnsupportObjectException extends \DomainException
 {
-    public function __construct($object, $code = 0, ?\Throwable $previous = null)
+    public function __construct(object $object, int $code = 0, ?\Throwable $previous = null)
     {
         $message = sprintf('Unhandled object of class %s', $object::class);
         parent::__construct($message, $code, $previous);
diff --git a/src/Factory/LogDataFactory.php b/src/Factory/LogDataFactory.php
index aa006b7..1025203 100644
--- a/src/Factory/LogDataFactory.php
+++ b/src/Factory/LogDataFactory.php
@@ -11,6 +11,10 @@
 /** @phpstan-type LogData array{entity: object, entityColumn: string, entityOldValue: ?string} */
 class LogDataFactory
 {
+    /**
+     * @param list<class-string> $includedEntities
+     * @param list<class-string> $excludedEntities
+     */
     public function __construct(
         private readonly LogSerializer $formatter,
         private readonly array $includedEntities,
@@ -54,7 +58,7 @@ public function createFromEvent(OnFlushEventArgs $eventArgs): iterable
         }
     }
 
-    private function isLoggable($entity): bool
+    private function isLoggable(object $entity): bool
     {
         if ($this->isSubClassFromList($entity, $this->excludedEntities)) {
             return false;
@@ -63,7 +67,10 @@ private function isLoggable($entity): bool
         return [] === $this->includedEntities || $this->isSubClassFromList($entity, $this->includedEntities);
     }
 
-    private function isSubClassFromList($entity, array $classes): bool
+    /**
+     * @param list<class-string> $classes
+     */
+    private function isSubClassFromList(object $entity, array $classes): bool
     {
         foreach ($classes as $class) {
             if (is_a($entity, $class)) {
@@ -75,7 +82,7 @@ private function isSubClassFromList($entity, array $classes): bool
     }
 
     /** @return LogData[] */
-    private function getLogsForEntityFields($entity, EntityManagerInterface $entityManager): iterable
+    private function getLogsForEntityFields(object $entity, EntityManagerInterface $entityManager): iterable
     {
         $unitOfWork = $entityManager->getUnitOfWork();
 
diff --git a/src/Serializer/LogSerializer.php b/src/Serializer/LogSerializer.php
index 7071b82..bc8ec05 100755
--- a/src/Serializer/LogSerializer.php
+++ b/src/Serializer/LogSerializer.php
@@ -47,12 +47,12 @@ public function formatEntity(EntityManagerInterface $entityManager, object $enti
             }
         }
 
-        return json_encode($data, JSON_PRETTY_PRINT);
+        return (string) json_encode($data, JSON_PRETTY_PRINT);
     }
 
-    public function formatValueAsString($value): string
+    public function formatValueAsString(mixed $value): string
     {
-        return json_encode($this->formatValue($value));
+        return (string) json_encode($this->formatValue($value));
     }
 
     /**
@@ -71,13 +71,13 @@ private function formatField(object $entity, string $field): mixed
     /**
      * Returns a formatted value depending on the given value's type.
      */
-    private function formatValue($value): mixed
+    private function formatValue(mixed $value): mixed
     {
         return match (gettype($value)) {
             'string' => mb_substr($value, 0, Log::MAX_STRING_LENGTH),
             'NULL', 'boolean', 'double', 'integer' => $value,
             'object' => $this->formatObject($value),
-            'array' => array_map(__METHOD__, $value),
+            'array' => array_map($this->formatValue(...), $value),
             'resource', 'resource (closed)', 'unknown type'
                 => throw new \InvalidArgumentException('Unhandled type'),
         };
diff --git a/tests/Factory/LogDataFactoryTest.php b/tests/Factory/LogDataFactoryTest.php
index 95d39e6..8e4c0ba 100644
--- a/tests/Factory/LogDataFactoryTest.php
+++ b/tests/Factory/LogDataFactoryTest.php
@@ -19,6 +19,7 @@ class LogDataFactoryTest extends KernelTestCase
     public function testExcludedEntityIsIgnored(): void
     {
         $em = self::getContainer()->get(EntityManagerInterface::class);
+        self::assertInstanceOf(EntityManagerInterface::class, $em);
         $em->persist(new Author());
         $em->getUnitOfWork()->computeChangeSets();
 
@@ -31,6 +32,7 @@ public function testExcludedEntityIsIgnored(): void
     public function testNewEntityIsLogged(): void
     {
         $em = self::getContainer()->get(EntityManagerInterface::class);
+        self::assertInstanceOf(EntityManagerInterface::class, $em);
         $em->persist($createdAuthor = new Author());
         $em->getUnitOfWork()->computeChangeSets();
 
@@ -94,6 +96,7 @@ public function testUpdatedEntityIsLogged(): void
     private function mockEntityManager(): array
     {
         $emReal = self::getContainer()->get(EntityManagerInterface::class);
+        self::assertInstanceOf(EntityManagerInterface::class, $emReal);
         $em = $this->createMock(EntityManagerInterface::class);
 
         $unitOfWork = $this->createMock(UnitOfWork::class);
diff --git a/tests/Functional/Entity/Address.php b/tests/Functional/Entity/Address.php
index e5ea238..c5569e9 100755
--- a/tests/Functional/Entity/Address.php
+++ b/tests/Functional/Entity/Address.php
@@ -9,6 +9,7 @@
 #[ORM\Entity]
 class Address extends AbstractEntity
 {
+    /** @phpstan-ignore property.unusedType */
     private ?string $streetName = null;
 
     public function __construct()
diff --git a/tests/Functional/Entity/FunctionalLog.php b/tests/Functional/Entity/FunctionalLog.php
index c41f356..d3805bb 100755
--- a/tests/Functional/Entity/FunctionalLog.php
+++ b/tests/Functional/Entity/FunctionalLog.php
@@ -22,6 +22,7 @@ public function __construct(
         string $requestTrace,
     ) {
         $this->id = Uuid::uuid1();
+        /** @phpstan-ignore method.notFound */
         $this->entityId = (string) $entity->getId();
         parent::__construct(
             $entity,
diff --git a/tests/Functional/Entity/Post.php b/tests/Functional/Entity/Post.php
index d21fcd9..da9c897 100755
--- a/tests/Functional/Entity/Post.php
+++ b/tests/Functional/Entity/Post.php
@@ -21,7 +21,7 @@ public function __construct(
     }
 
     #[Assert\NotBlank]
-    protected $title;
+    protected ?string $title = null;
 
     #[ORM\ManyToOne(targetEntity: Author::class, inversedBy: 'posts')]
     protected Author $author;
@@ -31,9 +31,11 @@ public function getAuthor(): Author
         return $this->author;
     }
 
+    /** @var ArrayCollection<int, Tag> */
     #[ORM\ManyToMany(targetEntity: Tag::class, inversedBy: 'posts')]
     protected ArrayCollection $tags;
 
+    /** @return Collection<int, Tag> */
     public function getTags(): Collection
     {
         return $this->tags;
diff --git a/tests/Functional/Entity/Tag.php b/tests/Functional/Entity/Tag.php
index 04cd666..7e589ec 100755
--- a/tests/Functional/Entity/Tag.php
+++ b/tests/Functional/Entity/Tag.php
@@ -16,6 +16,7 @@ public function __construct()
         $this->posts = new ArrayCollection();
     }
 
+    /** @var ArrayCollection<int, Post> */
     #[ORM\ManyToMany(Post::class, 'tags')]
     protected ArrayCollection $posts;
 
diff --git a/tests/Serializer/LogSerializerTest.php b/tests/Serializer/LogSerializerTest.php
index 45eff35..0db8f62 100755
--- a/tests/Serializer/LogSerializerTest.php
+++ b/tests/Serializer/LogSerializerTest.php
@@ -34,8 +34,10 @@ public function testFormatEntity(): void
         $post->addTag($tag);
 
         $entityManager = self::getContainer()->get(EntityManagerInterface::class);
+        self::assertInstanceOf(EntityManagerInterface::class, $entityManager);
 
         $formatter = self::getContainer()->get(LogSerializer::class);
+        self::assertInstanceOf(LogSerializer::class, $formatter);
         self::assertSame(
             json_encode(array_merge(
                 $this->helperFormatEntity($author),
@@ -64,6 +66,7 @@ public function testFormatEntity(): void
         );
     }
 
+    /** @return array<string, mixed> */
     public function helperFormatEntity(AbstractEntity $entity): array
     {
         return [
@@ -76,13 +79,13 @@ public function helperFormatEntity(AbstractEntity $entity): array
     /**
      * @dataProvider providerFormatValueAsString
      */
-    public function testFormatValueAsStringWorks($value, $formatted): void
+    public function testFormatValueAsStringWorks(mixed $value, string $formatted): void
     {
         $formatter = new LogSerializer();
         self::assertSame($formatted, $formatter->formatValueAsString($value));
     }
 
-    public function providerFormatValueAsString(): iterable
+    public static function providerFormatValueAsString(): iterable
     {
         yield [null, 'null'];
         yield [[null], '[null]'];
diff --git a/tests/Subscriber/LoggerSubscriberTest.php b/tests/Subscriber/LoggerSubscriberTest.php
index a64405b..17a91dc 100755
--- a/tests/Subscriber/LoggerSubscriberTest.php
+++ b/tests/Subscriber/LoggerSubscriberTest.php
@@ -66,7 +66,7 @@ public function testSubscriberPersistsLogs(): void
         $subscriber = new LoggerSubscriber(
             $logFactory,
             $logDataFactory,
-            realpath(__DIR__ .  '/../..')
+            (string) realpath(__DIR__ .  '/../..')
         );
 
         $subscriber->onFlush($event);