diff --git a/src/Serializer/Normalizer/AggregateIdNormalizer.php b/src/Serializer/Normalizer/AggregateIdNormalizer.php
new file mode 100644
index 000000000..58ee87171
--- /dev/null
+++ b/src/Serializer/Normalizer/AggregateIdNormalizer.php
@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Serializer\Normalizer;
+
+use Attribute;
+use Cspray\Phinal\AllowInheritance;
+use Patchlevel\EventSourcing\Aggregate\AggregateRootId;
+use Patchlevel\Hydrator\Normalizer\InvalidArgument;
+use Patchlevel\Hydrator\Normalizer\Normalizer;
+
+use function is_string;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+#[AllowInheritance('you can make specific normalizers for different classes')]
+class AggregateIdNormalizer implements Normalizer
+{
+    public function __construct(
+        /** @var class-string<AggregateRootId> */
+        private readonly string $aggregateIdClass,
+    ) {
+    }
+
+    public function normalize(mixed $value): string|null
+    {
+        if ($value === null) {
+            return null;
+        }
+
+        if (!$value instanceof AggregateRootId) {
+            throw InvalidArgument::withWrongType($this->aggregateIdClass, $value);
+        }
+
+        return $value->toString();
+    }
+
+    public function denormalize(mixed $value): AggregateRootId|null
+    {
+        if ($value === null) {
+            return null;
+        }
+
+        if (!is_string($value)) {
+            throw InvalidArgument::withWrongType('string', $value);
+        }
+
+        $class = $this->aggregateIdClass;
+
+        return $class::fromString($value);
+    }
+}
diff --git a/tests/Unit/Serializer/Normalizer/AggregateIdNormalizerTest.php b/tests/Unit/Serializer/Normalizer/AggregateIdNormalizerTest.php
new file mode 100644
index 000000000..40d2165df
--- /dev/null
+++ b/tests/Unit/Serializer/Normalizer/AggregateIdNormalizerTest.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Tests\Unit\Serializer\Normalizer;
+
+use Attribute;
+use Patchlevel\EventSourcing\Aggregate\BasicAggregateRootId;
+use Patchlevel\EventSourcing\Aggregate\UuidAggregateRootId;
+use Patchlevel\EventSourcing\Serializer\Normalizer\AggregateIdNormalizer;
+use Patchlevel\Hydrator\Normalizer\InvalidArgument;
+use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
+use Ramsey\Uuid\Exception\InvalidUuidStringException;
+
+#[Attribute(Attribute::TARGET_PROPERTY)]
+final class AggregateIdNormalizerTest extends TestCase
+{
+    use ProphecyTrait;
+
+    public function testNormalizeWithNull(): void
+    {
+        $normalizer = new AggregateIdNormalizer(BasicAggregateRootId::class);
+        $this->assertEquals(null, $normalizer->normalize(null));
+    }
+
+    public function testDenormalizeWithNull(): void
+    {
+        $normalizer = new AggregateIdNormalizer(BasicAggregateRootId::class);
+        $this->assertEquals(null, $normalizer->denormalize(null));
+    }
+
+    public function testNormalizeWithInvalidArgument(): void
+    {
+        $this->expectException(InvalidArgument::class);
+        $this->expectExceptionMessage('type "Patchlevel\EventSourcing\Aggregate\BasicAggregateRootId" was expected but "string" was passed.');
+
+        $normalizer = new AggregateIdNormalizer(BasicAggregateRootId::class);
+        $normalizer->normalize('foo');
+    }
+
+    public function testDenormalizeWithInvalidArgument(): void
+    {
+        $this->expectException(InvalidUuidStringException::class);
+
+        $normalizer = new AggregateIdNormalizer(UuidAggregateRootId::class);
+        $normalizer->denormalize('foo');
+    }
+
+    public function testNormalizeWithValue(): void
+    {
+        $normalizer = new AggregateIdNormalizer(BasicAggregateRootId::class);
+        $this->assertEquals('foo', $normalizer->normalize(new BasicAggregateRootId('foo')));
+    }
+
+    public function testDenormalizeWithValue(): void
+    {
+        $normalizer = new AggregateIdNormalizer(BasicAggregateRootId::class);
+        $this->assertEquals(new BasicAggregateRootId('foo'), $normalizer->denormalize('foo'));
+    }
+}