diff --git a/psalm.xml b/psalm.xml
index 8db1592..12c91d1 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -19,6 +19,10 @@
     </projectFiles>
 
     <issueHandlers>
-        <PropertyNotSetInConstructor errorLevel="suppress"/>
+        <PropertyNotSetInConstructor>
+            <errorLevel type="suppress">
+                <referencedProperty name="Symfony\Component\Serializer\SerializerAwareTrait::$serializer"/>
+            </errorLevel>
+        </PropertyNotSetInConstructor>
     </issueHandlers>
 </psalm>
diff --git a/src/Symfony/Extensions/PropertyNameConverter.php b/src/Symfony/Extensions/PropertyNameConverter.php
index 7c0a263..64d5ccf 100644
--- a/src/Symfony/Extensions/PropertyNameConverter.php
+++ b/src/Symfony/Extensions/PropertyNameConverter.php
@@ -24,7 +24,7 @@ final class PropertyNameConverter implements NameConverterInterface
      *
      * @psalm-var array<string, string>
      */
-    private $localStorage;
+    private $localStorage = [];
 
     /**
      * {@inheritdoc}
diff --git a/tests/Symfony/SymfonyMessageSerializerTest.php b/tests/Symfony/SymfonyMessageSerializerTest.php
index 934ee95..743977d 100644
--- a/tests/Symfony/SymfonyMessageSerializerTest.php
+++ b/tests/Symfony/SymfonyMessageSerializerTest.php
@@ -244,48 +244,46 @@ static function (Author $author): string
     /**
      * @test
      *
+     * @requires PHP >= 7.4
+     *
      * @throws \Throwable
      */
     public function legacyPropertiesSupport(): void
     {
-        if (\PHP_VERSION_ID >= 70400)
-        {
-            $serializer = new SymfonyMessageSerializer();
-
-            $object = new MixedWithLegacy(
-                'qwerty',
-                new \DateTimeImmutable('2019-01-01', new \DateTimeZone('UTC')),
-                100500
-            );
-
-            /** @var MixedWithLegacy $unserialized */
-            $unserialized = $serializer->decode($serializer->encode($object));
-
-            static::assertSame($object->string, $unserialized->string);
-            static::assertSame($object->dateTime->getTimestamp(), $unserialized->dateTime->getTimestamp());
-            static::assertSame($object->long, $unserialized->long);
-        }
+        $serializer = new SymfonyMessageSerializer();
+
+        $object = new MixedWithLegacy(
+            'qwerty',
+            new \DateTimeImmutable('2019-01-01', new \DateTimeZone('UTC')),
+            100500
+        );
+
+        /** @var MixedWithLegacy $unserialized */
+        $unserialized = $serializer->decode($serializer->encode($object));
+
+        static::assertSame($object->string, $unserialized->string);
+        static::assertSame($object->dateTime->getTimestamp(), $unserialized->dateTime->getTimestamp());
+        static::assertSame($object->long, $unserialized->long);
     }
 
     /**
      * @test
      *
+     * @requires PHP >= 7.4
+     *
      * @throws \Throwable
      */
     public function privateMixedPropertiesSupport(): void
     {
-        if (\PHP_VERSION_ID >= 70400)
-        {
-            $serializer = new SymfonyMessageSerializer();
-
-            $object = new WithPrivateProperties(
-                'Some string',
-                100500,
-                now()
-            );
-
-            /** @var WithPrivateProperties $unserialized */
-            $unserialized = $serializer->decode($serializer->encode($object));
-        }
+        $serializer = new SymfonyMessageSerializer();
+
+        $object = new WithPrivateProperties(
+            'Some string',
+            100500,
+            now()
+        );
+
+        /** @var WithPrivateProperties $unserialized */
+        $unserialized = $serializer->decode($serializer->encode($object));
     }
 }