diff --git a/README.md b/README.md
index a7ae32823..d73cb69e0 100644
--- a/README.md
+++ b/README.md
@@ -96,13 +96,16 @@ use App\Domain\Profile\Email;
 use App\Domain\Profile\ProfileId;
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{profileId: string, email: string}>
+ */
 final class ProfileCreated extends AggregateChanged
 {
     public static function raise(
         ProfileId $id,
         Email $email
     ): AggregateChanged {
-        return self::occur(
+        return new self(
             $id->toString(),
             [
                 'profileId' => $id->toString(),
diff --git a/baseline.xml b/baseline.xml
index 7e86b12db..495bd4d74 100644
--- a/baseline.xml
+++ b/baseline.xml
@@ -1,13 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <files psalm-version="4.13.1@5cf660f63b548ccd4a56f62d916ee4d6028e01a3">
+  <file src="src/Pipeline/Middleware/FilterEventMiddleware.php">
+    <MixedPropertyTypeCoercion occurrences="1">
+      <code>$callable</code>
+    </MixedPropertyTypeCoercion>
+  </file>
   <file src="tests/Integration/BasicImplementation/Aggregate/Profile.php">
     <MoreSpecificImplementedParamType occurrences="1">
       <code>$payload</code>
     </MoreSpecificImplementedParamType>
   </file>
-  <file src="tests/Integration/Pipeline/PipelineChangeStoreTest.php">
-    <ArgumentTypeCoercion occurrences="1"/>
-  </file>
   <file src="tests/Unit/Aggregate/AggregateChangedTest.php">
     <InvalidArgument occurrences="2"/>
   </file>
@@ -30,21 +32,6 @@
       <code>$text</code>
     </PropertyNotSetInConstructor>
   </file>
-  <file src="tests/Unit/Fixture/MessagePublished.php">
-    <MixedArgument occurrences="1">
-      <code>$this-&gt;payload['message']</code>
-    </MixedArgument>
-  </file>
-  <file src="tests/Unit/Fixture/ProfileCreated.php">
-    <MixedArgument occurrences="1">
-      <code>$this-&gt;payload['email']</code>
-    </MixedArgument>
-  </file>
-  <file src="tests/Unit/Fixture/ProfileVisited.php">
-    <MixedArgument occurrences="1">
-      <code>$this-&gt;payload['visitorId']</code>
-    </MixedArgument>
-  </file>
   <file src="tests/Unit/Fixture/ProfileWithSnapshot.php">
     <LessSpecificImplementedReturnType occurrences="1">
       <code>SnapshotableAggregateRoot</code>
@@ -53,9 +40,6 @@
       <code>$payload</code>
     </MoreSpecificImplementedParamType>
   </file>
-  <file src="tests/Unit/Pipeline/Middleware/ReplaceEventMiddlewareTest.php">
-    <ArgumentTypeCoercion occurrences="2"/>
-  </file>
   <file src="tests/Unit/Pipeline/Middleware/UntilEventMiddlewareTest.php">
     <InvalidArgument occurrences="1"/>
   </file>
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 9c96c4092..590e93114 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -13,6 +13,9 @@
 
     <rule ref="PatchlevelCodingStandard">
         <exclude name="SlevomatCodingStandard.Classes.SuperfluousExceptionNaming.SuperfluousSuffix" />
+        <exclude name="SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingTraversableTypeHintSpecification" />
+        <exclude name="SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingTraversableTypeHintSpecification" />
+        <exclude name="SlevomatCodingStandard.TypeHints.PropertyTypeHint.MissingTraversableTypeHintSpecification" />
         <exclude name="Generic.Files.LineLength.TooLong"/>
     </rule>
 </ruleset>
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index a04f229d5..16239a0d2 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -1,12 +1,97 @@
 parameters:
 	ignoreErrors:
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged\\:\\:serialize\\(\\) return type with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged does not specify its types\\: T$#"
+			count: 1
+			path: src/Aggregate/AggregateChanged.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateRoot\\:\\:apply\\(\\) has parameter \\$event with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/Aggregate/AggregateRoot.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateRoot\\:\\:createFromEventStream\\(\\) has parameter \\$stream with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/Aggregate/AggregateRoot.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateRoot\\:\\:releaseEvents\\(\\) return type with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged does not specify its types\\: T$#"
+			count: 1
+			path: src/Aggregate/AggregateRoot.php
+
+		-
+			message: "#^Property Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateRoot\\:\\:\\$uncommittedEvents with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged does not specify its types\\: T$#"
+			count: 1
+			path: src/Aggregate/AggregateRoot.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Aggregate\\\\ApplyMethodNotFound\\:\\:__construct\\(\\) has parameter \\$event with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/Aggregate/ApplyMethodNotFound.php
+
 		-
 			message: "#^Method Patchlevel\\\\EventSourcing\\\\Console\\\\DoctrineHelper\\:\\:databaseName\\(\\) should return string but returns mixed\\.$#"
 			count: 2
 			path: src/Console/DoctrineHelper.php
 
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Console\\\\EventPrinter\\:\\:write\\(\\) has parameter \\$event with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/Console/EventPrinter.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Pipeline\\\\Middleware\\\\ExcludeEventMiddleware\\:\\:__construct\\(\\) has parameter \\$classes with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/Pipeline/Middleware/ExcludeEventMiddleware.php
+
+		-
+			message: "#^Property Patchlevel\\\\EventSourcing\\\\Pipeline\\\\Middleware\\\\ExcludeEventMiddleware\\:\\:\\$classes with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged does not specify its types\\: T$#"
+			count: 1
+			path: src/Pipeline/Middleware/ExcludeEventMiddleware.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Pipeline\\\\Middleware\\\\FilterEventMiddleware\\:\\:__construct\\(\\) has parameter \\$callable with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/Pipeline/Middleware/FilterEventMiddleware.php
+
+		-
+			message: "#^Property Patchlevel\\\\EventSourcing\\\\Pipeline\\\\Middleware\\\\FilterEventMiddleware\\:\\:\\$callable with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged does not specify its types\\: T$#"
+			count: 1
+			path: src/Pipeline/Middleware/FilterEventMiddleware.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\Pipeline\\\\Middleware\\\\IncludeEventMiddleware\\:\\:__construct\\(\\) has parameter \\$classes with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/Pipeline/Middleware/IncludeEventMiddleware.php
+
+		-
+			message: "#^Property Patchlevel\\\\EventSourcing\\\\Pipeline\\\\Middleware\\\\IncludeEventMiddleware\\:\\:\\$classes with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged does not specify its types\\: T$#"
+			count: 1
+			path: src/Pipeline/Middleware/IncludeEventMiddleware.php
+
+		-
+			message: "#^Unable to resolve the template type E in call to method static method Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged\\<array\\<string, mixed\\>\\>\\:\\:deserialize\\(\\)$#"
+			count: 1
+			path: src/Store/MultiTableStore.php
+
+		-
+			message: "#^Unable to resolve the template type T in call to method static method Patchlevel\\\\EventSourcing\\\\Store\\\\DoctrineStore\\:\\:normalizeResult\\(\\)$#"
+			count: 1
+			path: src/Store/MultiTableStore.php
+
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\WatchServer\\\\WatchServer\\:\\:listen\\(\\) has parameter \\$callback with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/WatchServer/WatchServer.php
+
 		-
 			message: "#^While loop condition is always true\\.$#"
 			count: 1
 			path: src/WatchServer/WatchServer.php
 
+		-
+			message: "#^Method Patchlevel\\\\EventSourcing\\\\WatchServer\\\\WatchServerClient\\:\\:send\\(\\) has parameter \\$event with generic class Patchlevel\\\\EventSourcing\\\\Aggregate\\\\AggregateChanged but does not specify its types\\: T$#"
+			count: 1
+			path: src/WatchServer/WatchServerClient.php
+
diff --git a/src/Aggregate/AggregateChanged.php b/src/Aggregate/AggregateChanged.php
index e8221d9c1..9c1a80425 100644
--- a/src/Aggregate/AggregateChanged.php
+++ b/src/Aggregate/AggregateChanged.php
@@ -11,19 +11,26 @@
 
 use const JSON_THROW_ON_ERROR;
 
+/**
+ * @template-covariant T of array<string, mixed>
+ */
 abstract class AggregateChanged
 {
+    /** @readonly */
     protected string $aggregateId;
 
-    /** @var array<string, mixed> */
+    /**
+     * @readonly
+     * @var T
+     */
     protected array $payload;
     private ?int $playhead;
     private ?DateTimeImmutable $recordedOn;
 
     /**
-     * @param array<string, mixed> $payload
+     * @param T $payload
      */
-    final private function __construct(string $aggregateId, array $payload = [])
+    final public function __construct(string $aggregateId, array $payload = [])
     {
         $this->aggregateId = $aggregateId;
         $this->payload = $payload;
@@ -47,23 +54,13 @@ public function recordedOn(): ?DateTimeImmutable
     }
 
     /**
-     * @return array<string, mixed>
+     * @return T
      */
     public function payload(): array
     {
         return $this->payload;
     }
 
-    /**
-     * @param array<string, mixed> $payload
-     *
-     * @return static
-     */
-    protected static function occur(string $aggregateId, array $payload = []): self
-    {
-        return new static($aggregateId, $payload);
-    }
-
     /**
      * @internal
      *
@@ -75,6 +72,7 @@ public function recordNow(int $playhead): self
             throw new AggregateChangeRecordedAlready();
         }
 
+        /** @psalm-suppress UnsafeGenericInstantiation */
         $event = new static($this->aggregateId, $this->payload);
         $event->playhead = $playhead;
         $event->recordedOn = $this->createRecordDate();
@@ -83,7 +81,11 @@ public function recordNow(int $playhead): self
     }
 
     /**
-     * @param array{aggregateId: string, playhead: int, event: class-string<self>, payload: string, recordedOn: DateTimeImmutable} $data
+     * @param array{aggregateId: string, playhead: int, event: class-string<E>, payload: string, recordedOn: DateTimeImmutable} $data
+     *
+     * @return E
+     *
+     * @template E of self
      */
     public static function deserialize(array $data): self
     {
diff --git a/src/Aggregate/AggregateRoot.php b/src/Aggregate/AggregateRoot.php
index ba3169817..dfebf8bf2 100644
--- a/src/Aggregate/AggregateRoot.php
+++ b/src/Aggregate/AggregateRoot.php
@@ -20,6 +20,9 @@ abstract public function aggregateRootId(): string;
 
     abstract protected function apply(AggregateChanged $event): void;
 
+    /**
+     * @param AggregateChanged<array<string, mixed>> $event
+     */
     protected function record(AggregateChanged $event): void
     {
         $this->playhead++;
diff --git a/src/Aggregate/SnapshotableAggregateRoot.php b/src/Aggregate/SnapshotableAggregateRoot.php
index 94827b8c9..567deeb09 100644
--- a/src/Aggregate/SnapshotableAggregateRoot.php
+++ b/src/Aggregate/SnapshotableAggregateRoot.php
@@ -21,7 +21,7 @@ abstract protected function serialize(): array;
     abstract protected static function deserialize(array $payload): self;
 
     /**
-     * @param array<AggregateChanged> $stream
+     * @param array<AggregateChanged<array<string, mixed>>> $stream
      *
      * @return static
      */
diff --git a/src/EventBus/DefaultEventBus.php b/src/EventBus/DefaultEventBus.php
index 78745edcc..90e273d77 100644
--- a/src/EventBus/DefaultEventBus.php
+++ b/src/EventBus/DefaultEventBus.php
@@ -10,7 +10,7 @@
 
 final class DefaultEventBus implements EventBus
 {
-    /** @var list<AggregateChanged> */
+    /** @var list<AggregateChanged<array<string, mixed>>> */
     private array $queue;
     /**  @var list<Listener> */
     private array $listeners;
@@ -27,6 +27,9 @@ public function __construct(array $listeners = [])
         $this->processing = false;
     }
 
+    /**
+     * @param AggregateChanged<array<string, mixed>> $event
+     */
     public function dispatch(AggregateChanged $event): void
     {
         $this->queue[] = $event;
diff --git a/src/EventBus/EventBus.php b/src/EventBus/EventBus.php
index 5c5db4882..8221e6dd9 100644
--- a/src/EventBus/EventBus.php
+++ b/src/EventBus/EventBus.php
@@ -8,5 +8,8 @@
 
 interface EventBus
 {
+    /**
+     * @param AggregateChanged<array<string, mixed>> $event
+     */
     public function dispatch(AggregateChanged $event): void;
 }
diff --git a/src/EventBus/Listener.php b/src/EventBus/Listener.php
index 58c79d3a1..69280f42d 100644
--- a/src/EventBus/Listener.php
+++ b/src/EventBus/Listener.php
@@ -8,5 +8,8 @@
 
 interface Listener
 {
+    /**
+     * @param AggregateChanged<array<string, mixed>> $event
+     */
     public function __invoke(AggregateChanged $event): void;
 }
diff --git a/src/EventBus/SymfonyEventBus.php b/src/EventBus/SymfonyEventBus.php
index 49aef9297..8ed7a177d 100644
--- a/src/EventBus/SymfonyEventBus.php
+++ b/src/EventBus/SymfonyEventBus.php
@@ -21,6 +21,9 @@ public function __construct(MessageBusInterface $bus)
         $this->bus = $bus;
     }
 
+    /**
+     * @param AggregateChanged<array<string, mixed>> $event
+     */
     public function dispatch(AggregateChanged $event): void
     {
         $envelope = (new Envelope($event))
diff --git a/src/Pipeline/EventBucket.php b/src/Pipeline/EventBucket.php
index 11c030ce0..22622394c 100644
--- a/src/Pipeline/EventBucket.php
+++ b/src/Pipeline/EventBucket.php
@@ -12,10 +12,13 @@ class EventBucket
     /** @var class-string<AggregateRoot> */
     private string $aggregateClass;
     private int $index;
+
+    /** @var AggregateChanged<array<string, mixed>> */
     private AggregateChanged $event;
 
     /**
-     * @param class-string<AggregateRoot> $aggregateClass
+     * @param class-string<AggregateRoot>            $aggregateClass
+     * @param AggregateChanged<array<string, mixed>> $event
      */
     public function __construct(string $aggregateClass, int $index, AggregateChanged $event)
     {
@@ -37,6 +40,9 @@ public function index(): int
         return $this->index;
     }
 
+    /**
+     * @return AggregateChanged<array<string, mixed>>
+     */
     public function event(): AggregateChanged
     {
         return $this->event;
diff --git a/src/Pipeline/Middleware/ClassRenameMiddleware.php b/src/Pipeline/Middleware/ClassRenameMiddleware.php
index 5bb937e69..7c44d05f5 100644
--- a/src/Pipeline/Middleware/ClassRenameMiddleware.php
+++ b/src/Pipeline/Middleware/ClassRenameMiddleware.php
@@ -12,11 +12,11 @@
 
 class ClassRenameMiddleware implements Middleware
 {
-    /** @var array<class-string<AggregateChanged>, class-string<AggregateChanged>> */
+    /** @var array<class-string<AggregateChanged<array<string, mixed>>>, class-string<AggregateChanged<array<string, mixed>>>> */
     private array $classes;
 
     /**
-     * @param array<class-string<AggregateChanged>, class-string<AggregateChanged>> $classes
+     * @param array<class-string<AggregateChanged<array<string, mixed>>>, class-string<AggregateChanged<array<string, mixed>>>> $classes
      */
     public function __construct(array $classes)
     {
diff --git a/src/Pipeline/Middleware/ReplaceEventMiddleware.php b/src/Pipeline/Middleware/ReplaceEventMiddleware.php
index bf2f5f941..fd1441395 100644
--- a/src/Pipeline/Middleware/ReplaceEventMiddleware.php
+++ b/src/Pipeline/Middleware/ReplaceEventMiddleware.php
@@ -9,20 +9,23 @@
 use ReflectionClass;
 use ReflectionProperty;
 
+/**
+ * @template T of AggregateChanged
+ */
 class ReplaceEventMiddleware implements Middleware
 {
-    /** @var class-string<AggregateChanged> */
+    /** @var class-string<T> */
     private string $class;
 
-    /** @var callable(AggregateChanged $event):AggregateChanged */
+    /** @var callable(T $event):AggregateChanged<array<string, mixed>> */
     private $callable;
 
     private ReflectionProperty $recoredOnProperty;
     private ReflectionProperty $playheadProperty;
 
     /**
-     * @param class-string<AggregateChanged> $class
-     * @param callable(AggregateChanged      $event):AggregateChanged $callable
+     * @param class-string<T> $class
+     * @param callable(T      $event):AggregateChanged<array<string, mixed>> $callable
      */
     public function __construct(string $class, callable $callable)
     {
diff --git a/src/Projection/DefaultProjectionRepository.php b/src/Projection/DefaultProjectionRepository.php
index 2cb1f2935..23185bb27 100644
--- a/src/Projection/DefaultProjectionRepository.php
+++ b/src/Projection/DefaultProjectionRepository.php
@@ -28,6 +28,7 @@ public function handle(AggregateChanged $event): void
             $handlers = $projection->handledEvents();
 
             foreach ($handlers as $class => $method) {
+                /** @psalm-suppress DocblockTypeContradiction */
                 if (!$event instanceof $class) {
                     continue;
                 }
diff --git a/src/Projection/Projection.php b/src/Projection/Projection.php
index 2e623ce0e..fa09e0a59 100644
--- a/src/Projection/Projection.php
+++ b/src/Projection/Projection.php
@@ -8,7 +8,7 @@
 
 interface Projection
 {
-    /** @return iterable<class-string<AggregateChanged>, string> */
+    /** @return iterable<class-string<AggregateChanged<array<string, mixed>>>, string> */
     public function handledEvents(): iterable;
 
     public function create(): void;
diff --git a/src/Projection/ProjectionRepository.php b/src/Projection/ProjectionRepository.php
index 45a96e7d9..e5e7995a3 100644
--- a/src/Projection/ProjectionRepository.php
+++ b/src/Projection/ProjectionRepository.php
@@ -8,6 +8,9 @@
 
 interface ProjectionRepository
 {
+    /**
+     * @param AggregateChanged<array<string, mixed>> $event
+     */
     public function handle(AggregateChanged $event): void;
 
     public function create(): void;
diff --git a/src/Store/CorruptedMetadata.php b/src/Store/CorruptedMetadata.php
index befaaed7f..57a94287d 100644
--- a/src/Store/CorruptedMetadata.php
+++ b/src/Store/CorruptedMetadata.php
@@ -8,12 +8,20 @@
 
 final class CorruptedMetadata extends StoreException
 {
-    public function __construct(string $expectedId, string $actualId)
+    public static function fromEntryMismatch(string $expectedId, string $actualId): self
     {
-        parent::__construct(sprintf(
+        return new self(sprintf(
             'Corrupted metadata: expected id is %s get %s',
             $expectedId,
             $actualId
         ));
     }
+
+    public static function fromMissingEntry(string $expectedId): self
+    {
+        return new self(sprintf(
+            'Corrupted metadata: expected id is %s there but it is missing',
+            $expectedId
+        ));
+    }
 }
diff --git a/src/Store/DoctrineStore.php b/src/Store/DoctrineStore.php
index e3a7b1e9b..850ff88fe 100644
--- a/src/Store/DoctrineStore.php
+++ b/src/Store/DoctrineStore.php
@@ -10,7 +10,6 @@
 use Doctrine\DBAL\Schema\Schema;
 use Doctrine\DBAL\Types\Type;
 use Doctrine\DBAL\Types\Types;
-use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
 use function is_int;
 
@@ -31,9 +30,11 @@ public function connection(): Connection
     abstract public function schema(): Schema;
 
     /**
-     * @param array{aggregateId: string, playhead: string, event: class-string<AggregateChanged>, payload: string, recordedOn: string} $result
+     * @param array{aggregateId: string, playhead: string, event: class-string<T>, payload: string, recordedOn: string} $result
      *
-     * @return array{aggregateId: string, playhead: int, event: class-string<AggregateChanged>, payload: string, recordedOn: DateTimeImmutable}
+     * @return array{aggregateId: string, playhead: int, event: class-string<T>, payload: string, recordedOn: DateTimeImmutable}
+     *
+     * @template T
      */
     protected static function normalizeResult(AbstractPlatform $platform, array $result): array
     {
diff --git a/src/Store/MultiTableStore.php b/src/Store/MultiTableStore.php
index 70c6d89fb..2440bcf17 100644
--- a/src/Store/MultiTableStore.php
+++ b/src/Store/MultiTableStore.php
@@ -42,7 +42,7 @@ public function __construct(
     /**
      * @param class-string<AggregateRoot> $aggregate
      *
-     * @return array<AggregateChanged>
+     * @return array<AggregateChanged<array<string, mixed>>>
      */
     public function load(string $aggregate, string $id, int $fromPlayhead = 0): array
     {
@@ -54,7 +54,7 @@ public function load(string $aggregate, string $id, int $fromPlayhead = 0): arra
             ->where('aggregateId = :id AND playhead > :playhead')
             ->getSQL();
 
-        /** @var array<array{aggregateId: string, playhead: string, event: class-string<AggregateChanged>, payload: string, recordedOn: string}> $result */
+        /** @var array<array{aggregateId: string, playhead: string, event: class-string<AggregateChanged<array<string, mixed>>>, payload: string, recordedOn: string}> $result */
         $result = $this->connection->fetchAllAssociative(
             $sql,
             [
@@ -102,8 +102,8 @@ public function has(string $aggregate, string $id): bool
     }
 
     /**
-     * @param class-string<AggregateRoot> $aggregate
-     * @param array<AggregateChanged>     $events
+     * @param class-string<AggregateRoot>                   $aggregate
+     * @param array<AggregateChanged<array<string, mixed>>> $events
      */
     public function saveBatch(string $aggregate, string $id, array $events): void
     {
@@ -138,7 +138,9 @@ public function stream(int $fromIndex = 0): Generator
                 ->orderBy('id')
                 ->getSQL();
 
-            /** @var Traversable<array{id: string, aggregateId: string, playhead: string, event: class-string<AggregateChanged>, payload: string, recordedOn: string}> $query */
+            /**
+             * @var Traversable<array{id: string, aggregateId: string, playhead: string, event: class-string<AggregateChanged<array<string, mixed>>>, payload: string, recordedOn: string}> $query
+             */
             $query = $this->connection->iterateAssociative($sql, ['index' => $fromIndex]);
 
             if (!$query instanceof Generator) {
@@ -155,7 +157,9 @@ public function stream(int $fromIndex = 0): Generator
             ->orderBy('id')
             ->getSQL();
 
-        /** @var Traversable<array{id: string, aggregateId: string, playhead: string, aggregate: class-string<AggregateChanged>}> $metaQuery */
+        /**
+         * @var Traversable<array{id: string, aggregateId: string, playhead: string, aggregate: string}> $metaQuery
+         */
         $metaQuery = $this->connection->iterateAssociative($sql, ['index' => $fromIndex]);
 
         $platform = $this->connection->getDatabasePlatform();
@@ -169,10 +173,15 @@ public function stream(int $fromIndex = 0): Generator
             }
 
             $eventData = $queries[$name]->current();
+
+            if ($eventData === null) {
+                throw CorruptedMetadata::fromMissingEntry($metaData['id']);
+            }
+
             $queries[$name]->next();
 
             if ($eventData['id'] !== $metaData['id']) {
-                throw new CorruptedMetadata($metaData['id'], $eventData['id']);
+                throw CorruptedMetadata::fromEntryMismatch($metaData['id'], $eventData['id']);
             }
 
             yield new EventBucket(
@@ -211,14 +220,17 @@ public function saveEventBucket(EventBucket $bucket): void
         );
     }
 
-    private function saveEvent(Connection $connection, string $aggregate, AggregateChanged $event): void
+    /**
+     * @param AggregateChanged<array<string, mixed>> $event
+     */
+    private function saveEvent(Connection $connection, string $aggregateName, AggregateChanged $event): void
     {
         $data = $event->serialize();
 
         $connection->insert(
             $this->metadataTableName,
             [
-                'aggregate' => $aggregate,
+                'aggregate' => $aggregateName,
                 'aggregateId' => $data['aggregateId'],
                 'playhead' => $data['playhead'],
             ],
@@ -227,7 +239,7 @@ private function saveEvent(Connection $connection, string $aggregate, AggregateC
         $data['id'] = (int)$connection->lastInsertId();
 
         $connection->insert(
-            $aggregate,
+            $aggregateName,
             $data,
             [
                 'recordedOn' => Types::DATETIMETZ_IMMUTABLE,
diff --git a/src/Store/SingleTableStore.php b/src/Store/SingleTableStore.php
index 0c593e219..a41b80496 100644
--- a/src/Store/SingleTableStore.php
+++ b/src/Store/SingleTableStore.php
@@ -38,7 +38,7 @@ public function __construct(Connection $connection, array $aggregates, string $s
     /**
      * @param class-string<AggregateRoot> $aggregate
      *
-     * @return array<AggregateChanged>
+     * @return array<AggregateChanged<array<string, mixed>>>
      */
     public function load(string $aggregate, string $id, int $fromPlayhead = 0): array
     {
@@ -50,7 +50,7 @@ public function load(string $aggregate, string $id, int $fromPlayhead = 0): arra
             ->where('aggregate = :aggregate AND aggregateId = :id AND playhead > :playhead')
             ->getSQL();
 
-        /** @var array<array{aggregateId: string, playhead: string, event: class-string<AggregateChanged>, payload: string, recordedOn: string}> $result */
+        /** @var array<array{aggregateId: string, playhead: string, event: class-string<AggregateChanged<array<string, mixed>>>, payload: string, recordedOn: string}> $result */
         $result = $this->connection->fetchAllAssociative(
             $sql,
             [
@@ -102,8 +102,8 @@ public function has(string $aggregate, string $id): bool
     }
 
     /**
-     * @param class-string<AggregateRoot> $aggregate
-     * @param array<AggregateChanged>     $events
+     * @param class-string<AggregateRoot>                   $aggregate
+     * @param array<AggregateChanged<array<string, mixed>>> $events
      */
     public function saveBatch(string $aggregate, string $id, array $events): void
     {
@@ -144,7 +144,17 @@ public function stream(int $fromIndex = 0): Generator
             ->orderBy('id')
             ->getSQL();
 
-        /** @var array<array{id: string, aggregateId: string, aggregate: string, playhead: string, event: class-string<AggregateChanged>, payload: string, recordedOn: string}> $result */
+        /**
+         * @var array<array{
+         *     id: string,
+         *     aggregateId: string,
+         *     aggregate: string,
+         *     playhead: string,
+         *     event: class-string<AggregateChanged<array<string, mixed>>>,
+         *     payload: string,
+         *     recordedOn: string
+         * }> $result
+         */
         $result = $this->connection->iterateAssociative($sql, ['index' => $fromIndex]);
         $platform = $this->connection->getDatabasePlatform();
 
diff --git a/src/Store/Store.php b/src/Store/Store.php
index 147c9b25b..219d4a056 100644
--- a/src/Store/Store.php
+++ b/src/Store/Store.php
@@ -12,7 +12,7 @@ interface Store
     /**
      * @param class-string<AggregateRoot> $aggregate
      *
-     * @return array<AggregateChanged>
+     * @return array<AggregateChanged<array<string, mixed>>>
      */
     public function load(string $aggregate, string $id, int $fromPlayhead = 0): array;
 
@@ -22,8 +22,8 @@ public function load(string $aggregate, string $id, int $fromPlayhead = 0): arra
     public function has(string $aggregate, string $id): bool;
 
     /**
-     * @param class-string<AggregateRoot> $aggregate
-     * @param array<AggregateChanged>     $events
+     * @param class-string<AggregateRoot>                   $aggregate
+     * @param array<AggregateChanged<array<string, mixed>>> $events
      */
     public function saveBatch(string $aggregate, string $id, array $events): void;
 }
diff --git a/src/WatchServer/WatchServer.php b/src/WatchServer/WatchServer.php
index b68615ee1..3a6c30ac2 100644
--- a/src/WatchServer/WatchServer.php
+++ b/src/WatchServer/WatchServer.php
@@ -66,7 +66,7 @@ public function listen(callable $callback): void
         foreach ($this->messages($socket) as $clientId => $message) {
             $this->logger->info('Received a payload from client {clientId}', ['clientId' => $clientId]);
 
-            /** @var array{aggregateId: string, event: class-string<AggregateChanged>, payload: string, playhead: int, recordedOn: DateTimeImmutable} $payload */
+            /** @var array{aggregateId: string, event: class-string<AggregateChanged<array<string, mixed>>>, payload: string, playhead: int, recordedOn: DateTimeImmutable} $payload */
             $payload = unserialize(base64_decode($message), ['allowed_classes' => [DateTimeImmutable::class]]);
             $event = AggregateChanged::deserialize($payload);
 
diff --git a/tests/Integration/BasicImplementation/Events/ProfileCreated.php b/tests/Integration/BasicImplementation/Events/ProfileCreated.php
index c5021c3ad..63d597c5a 100644
--- a/tests/Integration/BasicImplementation/Events/ProfileCreated.php
+++ b/tests/Integration/BasicImplementation/Events/ProfileCreated.php
@@ -6,11 +6,14 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{id: string}>
+ */
 final class ProfileCreated extends AggregateChanged
 {
-    public static function raise(string $id): AggregateChanged
+    public static function raise(string $id): self
     {
-        return self::occur($id, ['id' => $id]);
+        return new self($id, ['id' => $id]);
     }
 
     public function profileId(): string
diff --git a/tests/Integration/BasicImplementation/Projection/ProfileProjection.php b/tests/Integration/BasicImplementation/Projection/ProfileProjection.php
index 13dcc835d..9a7baaba4 100644
--- a/tests/Integration/BasicImplementation/Projection/ProfileProjection.php
+++ b/tests/Integration/BasicImplementation/Projection/ProfileProjection.php
@@ -5,7 +5,6 @@
 namespace Patchlevel\EventSourcing\Tests\Integration\BasicImplementation\Projection;
 
 use Doctrine\DBAL\Connection;
-use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 use Patchlevel\EventSourcing\Projection\Projection;
 use Patchlevel\EventSourcing\Tests\Integration\BasicImplementation\Events\ProfileCreated;
 
@@ -18,7 +17,6 @@ public function __construct(Connection $connection)
         $this->connection = $connection;
     }
 
-    /** @return iterable<class-string<AggregateChanged>, string> */
     public function handledEvents(): iterable
     {
         yield ProfileCreated::class => 'applyProfileCreated';
diff --git a/tests/Integration/Pipeline/Events/NewVisited.php b/tests/Integration/Pipeline/Events/NewVisited.php
index 57836d9f8..b487a7ca1 100644
--- a/tests/Integration/Pipeline/Events/NewVisited.php
+++ b/tests/Integration/Pipeline/Events/NewVisited.php
@@ -6,11 +6,14 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{id: string}>
+ */
 final class NewVisited extends AggregateChanged
 {
-    public static function raise(string $id): AggregateChanged
+    public static function raise(string $id): self
     {
-        return self::occur($id, ['id' => $id]);
+        return new self($id, ['id' => $id]);
     }
 
     public function profileId(): string
diff --git a/tests/Integration/Pipeline/Events/OldVisited.php b/tests/Integration/Pipeline/Events/OldVisited.php
index ce002fa43..f51f0fc80 100644
--- a/tests/Integration/Pipeline/Events/OldVisited.php
+++ b/tests/Integration/Pipeline/Events/OldVisited.php
@@ -6,11 +6,14 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{id: string}>
+ */
 final class OldVisited extends AggregateChanged
 {
-    public static function raise(string $id): AggregateChanged
+    public static function raise(string $id): self
     {
-        return self::occur($id, ['id' => $id]);
+        return new self($id, ['id' => $id]);
     }
 
     public function profileId(): string
diff --git a/tests/Integration/Pipeline/Events/PrivacyAdded.php b/tests/Integration/Pipeline/Events/PrivacyAdded.php
index b2cc9cdb0..c14d08dd7 100644
--- a/tests/Integration/Pipeline/Events/PrivacyAdded.php
+++ b/tests/Integration/Pipeline/Events/PrivacyAdded.php
@@ -6,11 +6,14 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{id: string}>
+ */
 final class PrivacyAdded extends AggregateChanged
 {
-    public static function raise(string $id): AggregateChanged
+    public static function raise(string $id): self
     {
-        return self::occur($id, ['id' => $id]);
+        return new self($id, ['id' => $id]);
     }
 
     public function profileId(): string
diff --git a/tests/Integration/Pipeline/Events/ProfileCreated.php b/tests/Integration/Pipeline/Events/ProfileCreated.php
index 8dc093d0b..316d32b4d 100644
--- a/tests/Integration/Pipeline/Events/ProfileCreated.php
+++ b/tests/Integration/Pipeline/Events/ProfileCreated.php
@@ -6,11 +6,14 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{id: string}>
+ */
 final class ProfileCreated extends AggregateChanged
 {
-    public static function raise(string $id): AggregateChanged
+    public static function raise(string $id): self
     {
-        return self::occur($id, ['id' => $id]);
+        return new self($id, ['id' => $id]);
     }
 
     public function profileId(): string
diff --git a/tests/Unit/Fixture/MessagePublished.php b/tests/Unit/Fixture/MessagePublished.php
index 901e8ab57..0c0ffb336 100644
--- a/tests/Unit/Fixture/MessagePublished.php
+++ b/tests/Unit/Fixture/MessagePublished.php
@@ -6,13 +6,16 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{message: array{id: string, text: string, createdAt: string}}>
+ */
 final class MessagePublished extends AggregateChanged
 {
     public static function raise(
         ProfileId $id,
         Message $message
     ): self {
-        return self::occur(
+        return new self(
             $id->toString(),
             [
                 'message' => $message->toArray(),
diff --git a/tests/Unit/Fixture/ProfileCreated.php b/tests/Unit/Fixture/ProfileCreated.php
index 980379471..e76c7f101 100644
--- a/tests/Unit/Fixture/ProfileCreated.php
+++ b/tests/Unit/Fixture/ProfileCreated.php
@@ -6,13 +6,16 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{profileId: string, email: string}>
+ */
 class ProfileCreated extends AggregateChanged
 {
     public static function raise(
         ProfileId $id,
         Email $email
     ): self {
-        return self::occur(
+        return new self(
             $id->toString(),
             [
                 'profileId' => $id->toString(),
diff --git a/tests/Unit/Fixture/ProfileVisited.php b/tests/Unit/Fixture/ProfileVisited.php
index 4e676ef77..bb30c2708 100644
--- a/tests/Unit/Fixture/ProfileVisited.php
+++ b/tests/Unit/Fixture/ProfileVisited.php
@@ -6,11 +6,14 @@
 
 use Patchlevel\EventSourcing\Aggregate\AggregateChanged;
 
+/**
+ * @template-extends AggregateChanged<array{visitorId: string}>
+ */
 final class ProfileVisited extends AggregateChanged
 {
     public static function raise(ProfileId $visitedId, ProfileId $visitorId): self
     {
-        return self::occur(
+        return new self(
             $visitedId->toString(),
             [
                 'visitorId' => $visitorId->toString(),
diff --git a/tests/Unit/Pipeline/Middleware/ReplaceEventMiddlewareTest.php b/tests/Unit/Pipeline/Middleware/ReplaceEventMiddlewareTest.php
index 36a692f1a..d16a0aef9 100644
--- a/tests/Unit/Pipeline/Middleware/ReplaceEventMiddlewareTest.php
+++ b/tests/Unit/Pipeline/Middleware/ReplaceEventMiddlewareTest.php
@@ -50,6 +50,7 @@ static function (ProfileCreated $event) {
 
     public function testReplaceInvalidClass(): void
     {
+        /** @psalm-suppress InvalidArgument */
         $middleware = new ReplaceEventMiddleware(
             MessagePublished::class,
             static function (ProfileCreated $event) {
diff --git a/tests/Unit/Pipeline/Target/ProjectionTargetTest.php b/tests/Unit/Pipeline/Target/ProjectionTargetTest.php
index 7ed22e685..89d0f7dba 100644
--- a/tests/Unit/Pipeline/Target/ProjectionTargetTest.php
+++ b/tests/Unit/Pipeline/Target/ProjectionTargetTest.php
@@ -30,7 +30,6 @@ public function testSave(): void
         $projectionRepository = new class implements Projection {
             public static ?AggregateChanged $handledEvent = null;
 
-            /** @return iterable<class-string<AggregateChanged>, string> */
             public function handledEvents(): iterable
             {
                 yield ProfileCreated::class => 'applyProfileCreated';
diff --git a/tests/Unit/Projection/DefaultProjectionRepositoryTest.php b/tests/Unit/Projection/DefaultProjectionRepositoryTest.php
index ea0a2416e..1d44afb88 100644
--- a/tests/Unit/Projection/DefaultProjectionRepositoryTest.php
+++ b/tests/Unit/Projection/DefaultProjectionRepositoryTest.php
@@ -35,7 +35,6 @@ public function testHandle(): void
         $projection = new class implements Projection {
             public static ?AggregateChanged $handledEvent = null;
 
-            /** @return iterable<class-string<AggregateChanged>, string> */
             public function handledEvents(): iterable
             {
                 yield ProfileCreated::class => 'applyProfileCreated';
@@ -71,7 +70,6 @@ public function testHandleNotSupportedEvent(): void
         $projection = new class implements Projection {
             public static ?AggregateChanged $handledEvent = null;
 
-            /** @return iterable<class-string<AggregateChanged>, string> */
             public function handledEvents(): iterable
             {
                 yield ProfileCreated::class => 'applyProfileCreated';
@@ -105,7 +103,6 @@ public function drop(): void
     public function testHandleButProjectionsMethodIsMissing(): void
     {
         $projection = new class implements Projection {
-            /** @return iterable<class-string<AggregateChanged>, string> */
             public function handledEvents(): iterable
             {
                 yield ProfileCreated::class => 'applyProfileCreated';