diff --git a/compose.yaml b/compose.yaml
index 56e58e7..e8d8f18 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -6,8 +6,22 @@ services:
     environment:
       IN_CONTAINER: true
       HISTFILE: /workspace/var/.docker_history
+      THESIS_PGMQ_DSN: host=pgmq user=postgres password=postgres
     volumes:
       - .:/workspace
       - ~/.composer/cache:/composer/cache
     tty: true
     init: true
+    depends_on:
+      pgmq:
+        condition: service_healthy
+
+  pgmq:
+    image: ghcr.io/pgmq/pg18-pgmq:v1.11.1
+    environment:
+      POSTGRES_PASSWORD: postgres
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U postgres"]
+      interval: 2s
+      timeout: 5s
+      retries: 20
diff --git a/src/MessageBus/Handling/Handlers.php b/src/MessageBus/Handling/Handlers.php
index b55ba5f..9aacd48 100644
--- a/src/MessageBus/Handling/Handlers.php
+++ b/src/MessageBus/Handling/Handlers.php
@@ -54,7 +54,6 @@ public function with(string $messageClass, callable $handler, string $qualifier
         }
 
         $copy = clone $this;
-        /** @phpstan-ignore assign.propertyType */
         $copy->handlers[$messageClass][$qualifier] = $handler;
 
         return $copy;
diff --git a/tests/MessageBus/Pgmq/PgmqNotifyTriggerTest.php b/tests/MessageBus/Pgmq/PgmqNotifyTriggerTest.php
new file mode 100644
index 0000000..663403e
--- /dev/null
+++ b/tests/MessageBus/Pgmq/PgmqNotifyTriggerTest.php
@@ -0,0 +1,277 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Thesis\MessageBus\Pgmq;
+
+use Amp\DeferredFuture;
+use Amp\Future;
+use Amp\Postgres\PostgresConfig;
+use Amp\Postgres\PostgresConnection;
+use Amp\Postgres\PostgresConnectionPool;
+use Amp\TimeoutCancellation;
+use Testo\Assert;
+use Testo\Assert\ExpectNoAssertions;
+use Testo\Codecov\Covers;
+use Testo\Test;
+use Thesis\Headers;
+use Thesis\MessageBus\Transport\Consumer;
+use Thesis\MessageBus\Transport\ConsumerHandler;
+use Thesis\MessageBus\Transport\Disposition;
+use Thesis\MessageBus\Transport\InboundEnvelope;
+use Thesis\MessageBus\Transport\Operation;
+use Thesis\MessageBus\Transport\OutboundEnvelope;
+use Thesis\Pgmq;
+use Thesis\Time\TimeSpan;
+use function Amp\async;
+use function Amp\delay;
+
+#[Test]
+#[Covers(PgmqTransport::class)]
+final readonly class PgmqNotifyTriggerTest
+{
+    #[ExpectNoAssertions]
+    public function consumerStartDoesNotWaitForProducerTransactions(): void
+    {
+        $postgres = self::postgres();
+        $transport = new PgmqTransport($postgres);
+        $queue = self::createQueue($transport);
+
+        // A producer is in the middle of a transaction that has already inserted into the queue.
+        $producer = $postgres->beginTransaction();
+        $transport->dispatchInTransaction($producer, [self::envelope($queue)]);
+
+        // A worker (re)starts. Recreating the notify trigger takes a table lock that waits for every open producer
+        // transaction and blocks new inserts meanwhile, so the consumer must not touch it.
+        /** @var Future<Consumer> $start */
+        $start = async(static fn(): Consumer => $transport->startConsumer($queue, new SignallingHandler()));
+
+        try {
+            $start->await(new TimeoutCancellation(1));
+        } finally {
+            $producer->rollback();
+
+            $consumer = $start->await();
+            $consumer->stop();
+            $consumer->awaitCompletion();
+            Pgmq\dropQueue($postgres, $queue);
+        }
+    }
+
+    public function createdQueueWakesConsumerOnInsert(): void
+    {
+        $postgres = self::postgres();
+        $transport = new PgmqTransport($postgres, pollInterval: TimeSpan::fromSeconds(10));
+        $queue = self::createQueue($transport);
+
+        $handler = new SignallingHandler();
+        $consumer = $transport->startConsumer($queue, $handler);
+
+        try {
+            // Let the consumer make its initial (empty) read first, so only a notification can deliver the message.
+            delay(0.2);
+            $transport->dispatch([self::envelope($queue)]);
+
+            // Notifications are set up by createQueue(): the insert wakes the consumer long before the poll interval.
+            $handler->received->getFuture()->await(new TimeoutCancellation(2));
+        } finally {
+            $consumer->stop();
+            $consumer->awaitCompletion();
+            Pgmq\dropQueue($postgres, $queue);
+        }
+
+        Assert::true($handler->received->isComplete());
+    }
+
+    public function consumerStartRestoresNotificationsLostInCrashRecovery(): void
+    {
+        $postgres = self::postgres();
+        $transport = new PgmqTransport($postgres, pollInterval: TimeSpan::fromSeconds(10));
+        $queue = self::createQueue($transport);
+
+        // pgmq.notify_insert_throttle is UNLOGGED: crash recovery (or a promoted replica) leaves it empty, and the
+        // trigger notifies only when it finds the queue's row. A consumer (re)start must bring notifications back.
+        $postgres->execute('DELETE FROM pgmq.notify_insert_throttle WHERE queue_name = ?', [$queue]);
+
+        $handler = new SignallingHandler();
+        $consumer = $transport->startConsumer($queue, $handler);
+
+        try {
+            // Let the consumer make its initial (empty) read first, so only a notification can deliver the message.
+            delay(0.2);
+            $transport->dispatch([self::envelope($queue)]);
+
+            $handler->received->getFuture()->await(new TimeoutCancellation(2));
+        } finally {
+            $consumer->stop();
+            $consumer->awaitCompletion();
+            Pgmq\dropQueue($postgres, $queue);
+        }
+
+        Assert::true($handler->received->isComplete());
+    }
+
+    public function concurrentConsumerStartsCreateTheTriggerOnce(): void
+    {
+        $postgres = self::postgres();
+        $transport = new PgmqTransport($postgres);
+        $queue = self::createQueue($transport);
+        // Simulates a queue whose notifications are not set up (created before, or lost).
+        $postgres->execute('SELECT pgmq.disable_notify_insert(?)', [$queue]);
+
+        // A producer keeps an insert into the queue open, so the consumer starts are guaranteed to overlap.
+        $producer = $postgres->beginTransaction();
+        $transport->dispatchInTransaction($producer, [self::envelope($queue)]);
+
+        $failures = [];
+        $creations = self::countTriggerCreations($postgres, $queue, static function () use ($producer, $queue, &$failures): void {
+            $starts = [];
+
+            for ($i = 0; $i < 4; ++$i) {
+                // Each consumer has its own pool, as separate worker processes do.
+                $own = new PgmqTransport(self::postgres());
+                $starts[] = async(static fn(): Consumer => $own->startConsumer($queue, new SignallingHandler()));
+            }
+
+            delay(0.5);
+            $producer->rollback();
+
+            foreach ($starts as $start) {
+                try {
+                    /** @var Consumer $consumer */
+                    $consumer = $start->await(new TimeoutCancellation(5));
+                    $consumer->stop();
+                    $consumer->awaitCompletion();
+                } catch (\Throwable $e) {
+                    $failures[] = $e->getMessage();
+                }
+            }
+        });
+
+        Pgmq\dropQueue($postgres, $queue);
+
+        Assert::same($failures, []);
+        Assert::same($creations, 1);
+    }
+
+    public function consumerStartRestoresDisabledTrigger(): void
+    {
+        $postgres = self::postgres();
+        $transport = new PgmqTransport($postgres, pollInterval: TimeSpan::fromSeconds(10));
+        $queue = self::createQueue($transport);
+        $postgres->execute('SELECT pgmq.enable_notify_insert(?, 30)', [$queue]);
+        $postgres->query(\sprintf('ALTER TABLE pgmq.q_%s DISABLE TRIGGER trigger_notify_queue_insert_listeners', $queue));
+
+        $handler = new SignallingHandler();
+        $consumer = $transport->startConsumer($queue, $handler);
+
+        try {
+            // Let the consumer make its initial (empty) read first, so only a notification can deliver the message.
+            delay(0.2);
+            $transport->dispatch([self::envelope($queue)]);
+
+            $handler->received->getFuture()->await(new TimeoutCancellation(2));
+        } finally {
+            $consumer->stop();
+            $consumer->awaitCompletion();
+            Pgmq\dropQueue($postgres, $queue);
+        }
+
+        Assert::true($handler->received->isComplete());
+    }
+
+    /**
+     * Runs $action and returns how many times the notify trigger of the queue was created meanwhile (event trigger).
+     *
+     * @param non-empty-string $queue
+     * @param callable(): void $action
+     */
+    private static function countTriggerCreations(PostgresConnection $postgres, string $queue, callable $action): int
+    {
+        $postgres->query('CREATE TABLE IF NOT EXISTS public.thesis_test_ddl (object_identity text)');
+        $postgres->query('TRUNCATE public.thesis_test_ddl');
+        $postgres->query(<<<'SQL'
+            CREATE OR REPLACE FUNCTION public.thesis_test_log_ddl() RETURNS event_trigger LANGUAGE plpgsql AS $$
+            DECLARE r record;
+            BEGIN
+                FOR r IN SELECT * FROM pg_event_trigger_ddl_commands() LOOP
+                    INSERT INTO public.thesis_test_ddl (object_identity) VALUES (r.object_identity);
+                END LOOP;
+            END $$
+            SQL);
+        $postgres->query('DROP EVENT TRIGGER IF EXISTS thesis_test_ddl');
+        $postgres->query("CREATE EVENT TRIGGER thesis_test_ddl ON ddl_command_end WHEN TAG IN ('CREATE TRIGGER') EXECUTE FUNCTION public.thesis_test_log_ddl()");
+
+        try {
+            $action();
+        } finally {
+            $postgres->query('DROP EVENT TRIGGER IF EXISTS thesis_test_ddl');
+        }
+
+        /** @var array{n: int} $row */
+        $row = $postgres
+            ->execute('SELECT count(*)::int AS n FROM public.thesis_test_ddl WHERE object_identity LIKE ?', ['% on pgmq.q_' . $queue])
+            ->fetchRow();
+
+        return $row['n'];
+    }
+
+    private static function postgres(): PostgresConnection
+    {
+        $dsn = getenv('THESIS_PGMQ_DSN');
+
+        if (!\is_string($dsn) || $dsn === '') {
+            throw new \LogicException('Set the THESIS_PGMQ_DSN environment variable (see compose.yaml).');
+        }
+
+        return new PostgresConnectionPool(PostgresConfig::fromString($dsn));
+    }
+
+    /**
+     * @return non-empty-string
+     */
+    private static function createQueue(PgmqTransport $transport): string
+    {
+        $queue = 'q' . bin2hex(random_bytes(8));
+        $transport->createQueue($queue);
+
+        return $queue;
+    }
+
+    /**
+     * @param non-empty-string $queue
+     */
+    private static function envelope(string $queue): OutboundEnvelope
+    {
+        return new OutboundEnvelope(
+            operation: Operation::Send,
+            address: $queue,
+            payload: '{}',
+            headers: new Headers(),
+        );
+    }
+}
+
+/**
+ * @internal
+ */
+final readonly class SignallingHandler implements ConsumerHandler
+{
+    /** @var DeferredFuture<null> */
+    public DeferredFuture $received;
+
+    public function __construct()
+    {
+        $this->received = new DeferredFuture();
+    }
+
+    #[\Override]
+    public function handle(InboundEnvelope $envelope): Disposition
+    {
+        if (!$this->received->isComplete()) {
+            $this->received->complete();
+        }
+
+        return Disposition::Ack;
+    }
+}
diff --git a/tests/MessageBus/Pgmq/PgmqTransportTest.php b/tests/MessageBus/Pgmq/PgmqTransportTest.php
new file mode 100644
index 0000000..84923b3
--- /dev/null
+++ b/tests/MessageBus/Pgmq/PgmqTransportTest.php
@@ -0,0 +1,122 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Thesis\MessageBus\Pgmq;
+
+use Amp\DeferredFuture;
+use Amp\Postgres\PostgresConfig;
+use Amp\Postgres\PostgresConnection;
+use Amp\Postgres\PostgresConnectionPool;
+use Amp\TimeoutCancellation;
+use Testo\Assert;
+use Testo\Codecov\Covers;
+use Testo\Test;
+use Thesis\Headers;
+use Thesis\MessageBus\Transport\ConsumerHandler;
+use Thesis\MessageBus\Transport\Disposition;
+use Thesis\MessageBus\Transport\InboundEnvelope;
+use Thesis\MessageBus\Transport\Operation;
+use Thesis\MessageBus\Transport\OutboundEnvelope;
+use Thesis\Pgmq;
+use Thesis\Time\TimeSpan;
+
+#[Test]
+#[Covers(PgmqTransport::class)]
+final readonly class PgmqTransportTest
+{
+    public function consumerDrainsBacklogWithoutWaitingForPollInterval(): void
+    {
+        $postgres = self::postgres();
+        $queue = self::createQueue($postgres);
+        $transport = new PgmqTransport($postgres, batchSize: 10, pollInterval: TimeSpan::fromSeconds(10));
+        $transport->dispatch(self::envelopes($queue, 25));
+
+        $handler = new CountingHandler(25);
+        $consumer = $transport->startConsumer($queue, $handler);
+
+        try {
+            // The backlog is already there: no further inserts will wake the consumer up, so a full batch must
+            // trigger the next read immediately instead of waiting for the poll interval (2 x 10 s for 25 messages).
+            $handler->done->getFuture()->await(new TimeoutCancellation(2));
+        } finally {
+            $consumer->stop();
+            $consumer->awaitCompletion();
+            Pgmq\dropQueue($postgres, $queue);
+        }
+
+        Assert::same($handler->handled, 25);
+    }
+
+    private static function postgres(): PostgresConnection
+    {
+        $dsn = getenv('THESIS_PGMQ_DSN');
+
+        if (!\is_string($dsn) || $dsn === '') {
+            throw new \LogicException('Set the THESIS_PGMQ_DSN environment variable (see compose.yaml).');
+        }
+
+        return new PostgresConnectionPool(PostgresConfig::fromString($dsn));
+    }
+
+    /**
+     * @return non-empty-string
+     */
+    private static function createQueue(PostgresConnection $postgres): string
+    {
+        $queue = 'q' . bin2hex(random_bytes(8));
+        new PgmqTransport($postgres)->createQueue($queue);
+
+        return $queue;
+    }
+
+    /**
+     * @param non-empty-string $queue
+     * @param positive-int $count
+     * @return non-empty-list<OutboundEnvelope>
+     */
+    private static function envelopes(string $queue, int $count): array
+    {
+        return array_map(
+            static fn(int $index): OutboundEnvelope => new OutboundEnvelope(
+                operation: Operation::Send,
+                address: $queue,
+                payload: json_encode(['index' => $index], JSON_THROW_ON_ERROR),
+                headers: new Headers(),
+            ),
+            range(1, $count),
+        );
+    }
+}
+
+/**
+ * @internal
+ */
+final class CountingHandler implements ConsumerHandler
+{
+    public int $handled = 0;
+
+    /** @var DeferredFuture<null> */
+    public readonly DeferredFuture $done;
+
+    /**
+     * @param positive-int $expected
+     */
+    public function __construct(
+        private readonly int $expected,
+    ) {
+        $this->done = new DeferredFuture();
+    }
+
+    #[\Override]
+    public function handle(InboundEnvelope $envelope): Disposition
+    {
+        ++$this->handled;
+
+        if ($this->handled === $this->expected) {
+            $this->done->complete();
+        }
+
+        return Disposition::Ack;
+    }
+}