diff --git a/baseline.xml b/baseline.xml
index 6ba800a47..09621b43a 100644
--- a/baseline.xml
+++ b/baseline.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<files psalm-version="5.19.0@06b71be009a6bd6d81b9811855d6629b9fe90e1b">
+<files psalm-version="5.21.1@8c473e2437be8b6a8fd8f630f0f11a16b114c494">
   <file src="src/Aggregate/AggregateRootBehaviour.php">
     <UnsafeInstantiation>
       <code>new static()</code>
@@ -188,6 +188,23 @@
       <code>$name</code>
     </PropertyNotSetInConstructor>
   </file>
+  <file src="tests/Unit/EventBus/MessageTest.php">
+    <InvalidArgument>
+      <code><![CDATA[[
+                'foo' => 'bar',
+                'aggregateClass' => Profile::class,
+                'aggregateId' => '1',
+                'playhead' => 3,
+                'recordedOn' => $recordedAt,
+                'newStreamStart' => true,
+                'archived' => true,
+            ]]]></code>
+    </InvalidArgument>
+    <TypeDoesNotContainType>
+      <code>assertSame</code>
+      <code>assertSame</code>
+    </TypeDoesNotContainType>
+  </file>
   <file src="tests/Unit/Fixture/MessageNormalizer.php">
     <MixedArgumentTypeCoercion>
       <code>$value</code>
diff --git a/src/EventBus/Message.php b/src/EventBus/Message.php
index 537806fd7..b0e4de0a6 100644
--- a/src/EventBus/Message.php
+++ b/src/EventBus/Message.php
@@ -12,7 +12,14 @@
 /**
  * @template-covariant T of object
  * @psalm-immutable
- * @psalm-type Headers = array{aggregateClass?: class-string<AggregateRoot>, aggregateId?:string, playhead?:positive-int, recordedOn?: DateTimeImmutable, newStreamStart?: bool, archived?: bool}
+ * @psalm-type Headers = array{
+ *     aggregateClass?: class-string<AggregateRoot>,
+ *     aggregateId?: string,
+ *     playhead?: positive-int,
+ *     recordedOn?: DateTimeImmutable,
+ *     newStreamStart?: bool,
+ *     archived?: bool
+ *  }
  */
 final class Message
 {
diff --git a/tests/Unit/Aggregate/UuidTest.php b/tests/Unit/Aggregate/UuidTest.php
index c44fc0a64..cbeaa9497 100644
--- a/tests/Unit/Aggregate/UuidTest.php
+++ b/tests/Unit/Aggregate/UuidTest.php
@@ -4,6 +4,7 @@
 
 namespace Patchlevel\EventSourcing\Tests\Unit\Aggregate;
 
+use DateTimeInterface;
 use Patchlevel\EventSourcing\Aggregate\Uuid;
 use PHPUnit\Framework\TestCase;
 use Ramsey\Uuid\Uuid as RamseyUuid;
@@ -40,7 +41,7 @@ public function testV7(): void
     {
         $factory = new class extends UuidFactory
         {
-            public function uuid7($node = null, int|null $clockSeq = null): UuidInterface
+            public function uuid7(DateTimeInterface|null $dateTime = null): UuidInterface
             {
                 return RamseyUuid::fromString('018d6a97-6aba-7104-825f-67313a77a2a4');
             }
diff --git a/tests/Unit/EventBus/MessageTest.php b/tests/Unit/EventBus/MessageTest.php
index eea0075a2..70d135e6b 100644
--- a/tests/Unit/EventBus/MessageTest.php
+++ b/tests/Unit/EventBus/MessageTest.php
@@ -5,6 +5,7 @@
 namespace Patchlevel\EventSourcing\Tests\Unit\EventBus;
 
 use DateTimeImmutable;
+use Generator;
 use Patchlevel\EventSourcing\EventBus\HeaderNotFound;
 use Patchlevel\EventSourcing\EventBus\Message;
 use Patchlevel\EventSourcing\Tests\Unit\Fixture\Email;
@@ -220,7 +221,8 @@ public function testHeaderNotFound(string $headerName): void
         $message->{$headerName}();
     }
 
-    public static function provideHeaderNotFound()
+    /** @return Generator<string, array{string}> */
+    public static function provideHeaderNotFound(): Generator
     {
         yield 'aggregateClass' => ['aggregateClass'];
         yield 'aggregateId' => ['aggregateId'];
diff --git a/tests/Unit/Lock/DoctrineDbalStoreSchemaAdapterTest.php b/tests/Unit/Lock/DoctrineDbalStoreSchemaAdapterTest.php
index b3be3b7ef..2a820cf02 100644
--- a/tests/Unit/Lock/DoctrineDbalStoreSchemaAdapterTest.php
+++ b/tests/Unit/Lock/DoctrineDbalStoreSchemaAdapterTest.php
@@ -4,6 +4,7 @@
 
 namespace Patchlevel\EventSourcing\Tests\Unit\Lock;
 
+use Closure;
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\Schema\Schema;
 use Patchlevel\EventSourcing\Lock\DoctrineDbalStoreSchemaAdapter;
@@ -25,6 +26,7 @@ public function testConfigureSchema(): void
         //$store->configureSchema($schema, Argument::type('Closure'))->shouldBeCalledOnce();
 
         $store->configureSchema($schema, Argument::any())->shouldBeCalledOnce()->will(
+            /** @param array{1: Closure} $args */
             static function (array $args): void {
                 if (!$args[1]()) {
                     throw new RuntimeException();
diff --git a/tests/Unit/Snapshot/SnapshotNotConfiguredTest.php b/tests/Unit/Snapshot/SnapshotNotConfiguredTest.php
index 55001e4df..3a43ae7b4 100644
--- a/tests/Unit/Snapshot/SnapshotNotConfiguredTest.php
+++ b/tests/Unit/Snapshot/SnapshotNotConfiguredTest.php
@@ -5,6 +5,7 @@
 namespace Patchlevel\EventSourcing\Tests\Unit\Snapshot;
 
 use Patchlevel\EventSourcing\Snapshot\SnapshotNotConfigured;
+use Patchlevel\EventSourcing\Tests\Unit\Fixture\Profile;
 use PHPUnit\Framework\TestCase;
 
 /** @covers \Patchlevel\EventSourcing\Snapshot\SnapshotNotConfigured */
@@ -12,10 +13,10 @@ final class SnapshotNotConfiguredTest extends TestCase
 {
     public function testCreate(): void
     {
-        $exception = new SnapshotNotConfigured('Foo\Profile');
+        $exception = new SnapshotNotConfigured(Profile::class);
 
         self::assertSame(
-            'Missing snapshot configuration for the aggregate class "Foo\Profile"',
+            'Missing snapshot configuration for the aggregate class "Patchlevel\EventSourcing\Tests\Unit\Fixture\Profile"',
             $exception->getMessage(),
         );
         self::assertSame(0, $exception->getCode());
diff --git a/tests/Unit/Snapshot/SnapshotNotFoundTest.php b/tests/Unit/Snapshot/SnapshotNotFoundTest.php
index c95e44bf4..ee387fed7 100644
--- a/tests/Unit/Snapshot/SnapshotNotFoundTest.php
+++ b/tests/Unit/Snapshot/SnapshotNotFoundTest.php
@@ -7,6 +7,7 @@
 use Patchlevel\EventSourcing\Aggregate\AggregateRootId;
 use Patchlevel\EventSourcing\Aggregate\CustomIdBehaviour;
 use Patchlevel\EventSourcing\Snapshot\SnapshotNotFound;
+use Patchlevel\EventSourcing\Tests\Unit\Fixture\Profile;
 use PHPUnit\Framework\TestCase;
 
 /** @covers \Patchlevel\EventSourcing\Snapshot\SnapshotNotFound */
@@ -14,12 +15,12 @@ final class SnapshotNotFoundTest extends TestCase
 {
     public function testCreate(): void
     {
-        $exception = new SnapshotNotFound('Foo\Profile', new class ('1') implements AggregateRootId {
+        $exception = new SnapshotNotFound(Profile::class, new class ('1') implements AggregateRootId {
             use CustomIdBehaviour;
         });
 
         self::assertSame(
-            'snapshot for aggregate "Foo\Profile" with the id "1" not found',
+            'snapshot for aggregate "Patchlevel\EventSourcing\Tests\Unit\Fixture\Profile" with the id "1" not found',
             $exception->getMessage(),
         );
         self::assertSame(0, $exception->getCode());