diff --git a/Tests/Validator/Constraints/UniqueTest.php b/Tests/Validator/Constraints/UniqueTest.php
new file mode 100644
index 00000000..8931700c
--- /dev/null
+++ b/Tests/Validator/Constraints/UniqueTest.php
@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Bundle\MongoDBBundle\Tests\Validator\Constraints;
+
+use Doctrine\Bundle\MongoDBBundle\Validator\Constraints\Unique;
+use Doctrine\Common\Annotations\AnnotationReader;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Validator\Mapping\ClassMetadata;
+use Symfony\Component\Validator\Mapping\Loader\AnnotationLoader;
+
+use function assert;
+
+use const PHP_VERSION_ID;
+
+final class UniqueTest extends TestCase
+{
+    public function testWithDefaultProperty(): void
+    {
+        $metadata = new ClassMetadata(UniqueDocumentDummyOne::class);
+
+        if (PHP_VERSION_ID >= 80000) {
+            $loader = new AnnotationLoader();
+        } else {
+            $loader = new AnnotationLoader(new AnnotationReader());
+        }
+
+        self::assertTrue($loader->loadClassMetadata($metadata));
+
+        [$constraint] = $metadata->getConstraints();
+        assert($constraint instanceof Unique);
+        self::assertSame(['email'], $constraint->fields);
+        self::assertSame('doctrine_odm.mongodb.unique', $constraint->validatedBy());
+    }
+}
+
+/** @Unique(fields={"email"}) */
+#[Unique(['email'])]
+class UniqueDocumentDummyOne
+{
+    private string $email;
+}