diff --git a/pkg/redis/RedisProducer.php b/pkg/redis/RedisProducer.php
index 3721ed20a..cc7d63230 100644
--- a/pkg/redis/RedisProducer.php
+++ b/pkg/redis/RedisProducer.php
@@ -64,7 +64,7 @@ public function send(Destination $destination, Message $message): void
         $payload = $this->context->getSerializer()->toString($message);
 
         if ($message->getDeliveryDelay()) {
-            $deliveryAt = time() + $message->getDeliveryDelay();
+            $deliveryAt = time() + $message->getDeliveryDelay() / 1000;
             $this->context->getRedis()->zadd($destination->getName().':delayed', $payload, $deliveryAt);
         } else {
             $this->context->getRedis()->lpush($destination->getName(), $payload);
diff --git a/pkg/redis/Tests/RedisProducerTest.php b/pkg/redis/Tests/RedisProducerTest.php
index 12082734c..daef46b61 100644
--- a/pkg/redis/Tests/RedisProducerTest.php
+++ b/pkg/redis/Tests/RedisProducerTest.php
@@ -88,6 +88,45 @@ public function testShouldCallLPushOnSend()
         $producer->send($destination, new RedisMessage());
     }
 
+    /**
+     * Tests if Redis::zadd is called with the expected 'score' (used as delivery timestamp).
+     *
+     * @depends testShouldCallLPushOnSend
+     */
+    public function testShouldCallZaddOnSendWithDeliveryDelay()
+    {
+        $destination = new RedisDestination('aDestination');
+
+        $redisMock = $this->createRedisMock();
+        $redisMock
+            ->expects($this->once())
+            ->method('zadd')
+            ->with(
+                'aDestination:delayed',
+                $this->isJson(),
+                $this->equalTo(time() + 5)
+            )
+        ;
+
+        $context = $this->createContextMock();
+        $context
+            ->expects($this->once())
+            ->method('getRedis')
+            ->willReturn($redisMock)
+        ;
+        $context
+            ->expects($this->once())
+            ->method('getSerializer')
+            ->willReturn(new JsonSerializer())
+        ;
+
+        $message = new RedisMessage();
+        $message->setDeliveryDelay(5000); // 5 seconds in milliseconds
+
+        $producer = new RedisProducer($context);
+        $producer->send($destination, $message);
+    }
+
     /**
      * @return \PHPUnit_Framework_MockObject_MockObject|RedisContext
      */