diff --git a/composer.json b/composer.json
index 639b274b6..7fdbc11b9 100644
--- a/composer.json
+++ b/composer.json
@@ -11,8 +11,8 @@
     "ext-mongodb": "^1.3",
     "ext-rdkafka": "^3.0.3",
 
-    "queue-interop/amqp-interop": "^0.8",
-    "queue-interop/queue-interop": "^0.7|^0.8",
+    "queue-interop/amqp-interop": "dev-master",
+    "queue-interop/queue-interop": "dev-master",
     "bunny/bunny": "^0.2.4|^0.3|^0.4",
     "php-amqplib/php-amqplib": "^2.7",
     "doctrine/dbal": "^2.6",
@@ -55,6 +55,16 @@
     "kwn/php-rdkafka-stubs": "^1.0.2",
     "friendsofphp/php-cs-fixer": "^2"
   },
+  "repositories": [
+    {
+      "type": "vcs",
+      "url": "https://github.com/Sevavietl/queue-interop"
+    },
+    {
+      "type": "vcs",
+      "url": "https://github.com/Sevavietl/amqp-interop"
+    }
+  ],
   "autoload": {
     "psr-4": {
       "Enqueue\\AmqpBunny\\": "pkg/amqp-bunny/",
diff --git a/pkg/amqp-bunny/AmqpContext.php b/pkg/amqp-bunny/AmqpContext.php
index f57554335..552a251d7 100644
--- a/pkg/amqp-bunny/AmqpContext.php
+++ b/pkg/amqp-bunny/AmqpContext.php
@@ -71,9 +71,11 @@ public function __construct($bunnyChannel, array $config)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return InteropAmqpMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new AmqpMessage($body, $properties, $headers);
     }
diff --git a/pkg/amqp-ext/AmqpContext.php b/pkg/amqp-ext/AmqpContext.php
index 5ea099da2..16e324c28 100644
--- a/pkg/amqp-ext/AmqpContext.php
+++ b/pkg/amqp-ext/AmqpContext.php
@@ -54,9 +54,11 @@ public function __construct($extChannel)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return InteropAmqpMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new AmqpMessage($body, $properties, $headers);
     }
diff --git a/pkg/amqp-lib/AmqpContext.php b/pkg/amqp-lib/AmqpContext.php
index 83167c3db..f43153b16 100644
--- a/pkg/amqp-lib/AmqpContext.php
+++ b/pkg/amqp-lib/AmqpContext.php
@@ -60,9 +60,11 @@ public function __construct(AbstractConnection $connection, array $config)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return InteropAmqpMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new AmqpMessage($body, $properties, $headers);
     }
diff --git a/pkg/dbal/DbalContext.php b/pkg/dbal/DbalContext.php
index f6119481c..2d176f51e 100644
--- a/pkg/dbal/DbalContext.php
+++ b/pkg/dbal/DbalContext.php
@@ -64,7 +64,7 @@ public function __construct($connection, array $config = [])
     /**
      * {@inheritdoc}
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         $message = new DbalMessage();
         $message->setBody($body);
diff --git a/pkg/dbal/DbalMessage.php b/pkg/dbal/DbalMessage.php
index af62c1079..318542274 100644
--- a/pkg/dbal/DbalMessage.php
+++ b/pkg/dbal/DbalMessage.php
@@ -4,14 +4,12 @@
 
 namespace Enqueue\Dbal;
 
+use Interop\Queue\Impl\StringBodyOnlyTrait;
 use Interop\Queue\Message;
 
 class DbalMessage implements Message
 {
-    /**
-     * @var string
-     */
-    private $body;
+    use StringBodyOnlyTrait;
 
     /**
      * @var array
@@ -84,16 +82,6 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redeliverAfter = null;
     }
 
-    public function setBody(string $body): void
-    {
-        $this->body = $body;
-    }
-
-    public function getBody(): string
-    {
-        return $this->body;
-    }
-
     public function setProperties(array $properties): void
     {
         $this->properties = $properties;
diff --git a/pkg/dbal/DbalProducer.php b/pkg/dbal/DbalProducer.php
index 5435629eb..c31bd0e91 100644
--- a/pkg/dbal/DbalProducer.php
+++ b/pkg/dbal/DbalProducer.php
@@ -62,8 +62,6 @@ public function send(Destination $destination, Message $message): void
             $message->setTimeToLive($this->timeToLive);
         }
 
-        $body = $message->getBody();
-
         $publishedAt = null !== $message->getPublishedAt() ?
             $message->getPublishedAt() :
             (int) (microtime(true) * 10000)
@@ -72,7 +70,7 @@ public function send(Destination $destination, Message $message): void
         $dbalMessage = [
             'id' => Uuid::uuid4(),
             'published_at' => $publishedAt,
-            'body' => $body,
+            'body' => $message->getBody(),
             'headers' => JSON::encode($message->getHeaders()),
             'properties' => JSON::encode($message->getProperties()),
             'priority' => -1 * $message->getPriority(),
diff --git a/pkg/dbal/Tests/DbalConsumerTest.php b/pkg/dbal/Tests/DbalConsumerTest.php
index c042c5c86..b46e15f50 100644
--- a/pkg/dbal/Tests/DbalConsumerTest.php
+++ b/pkg/dbal/Tests/DbalConsumerTest.php
@@ -217,11 +217,11 @@ private function createConectionMock()
 
 class InvalidMessage implements Message
 {
-    public function getBody(): string
+    public function getBody()
     {
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
     }
 
diff --git a/pkg/fs/FsContext.php b/pkg/fs/FsContext.php
index 480074e03..f09b0b50f 100644
--- a/pkg/fs/FsContext.php
+++ b/pkg/fs/FsContext.php
@@ -58,9 +58,11 @@ public function __construct(string $storeDir, int $preFetchCount, int $chmod, in
     }
 
     /**
+     * @param mixed $body
+     *
      * @return FsMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new FsMessage($body, $properties, $headers);
     }
diff --git a/pkg/fs/FsMessage.php b/pkg/fs/FsMessage.php
index d66ee52cd..f99879416 100644
--- a/pkg/fs/FsMessage.php
+++ b/pkg/fs/FsMessage.php
@@ -9,7 +9,7 @@
 class FsMessage implements Message, \JsonSerializable
 {
     /**
-     * @var string
+     * @var string|int|float|array|\JsonSerializable
      */
     private $body;
 
@@ -28,7 +28,7 @@ class FsMessage implements Message, \JsonSerializable
      */
     private $redelivered;
 
-    public function __construct(string $body = '', array $properties = [], array $headers = [])
+    public function __construct($body = '', array $properties = [], array $headers = [])
     {
         $this->body = $body;
         $this->properties = $properties;
@@ -36,12 +36,12 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
         $this->body = $body;
     }
 
-    public function getBody(): string
+    public function getBody()
     {
         return $this->body;
     }
diff --git a/pkg/gearman/GearmanContext.php b/pkg/gearman/GearmanContext.php
index 80a93882e..3e8df8347 100644
--- a/pkg/gearman/GearmanContext.php
+++ b/pkg/gearman/GearmanContext.php
@@ -40,9 +40,11 @@ public function __construct(array $config)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return GearmanMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new GearmanMessage($body, $properties, $headers);
     }
diff --git a/pkg/gearman/GearmanMessage.php b/pkg/gearman/GearmanMessage.php
index 625566d62..4dc5e9ba2 100644
--- a/pkg/gearman/GearmanMessage.php
+++ b/pkg/gearman/GearmanMessage.php
@@ -9,7 +9,7 @@
 class GearmanMessage implements Message, \JsonSerializable
 {
     /**
-     * @var string
+     * @var string|int|float|array|\JsonSerializable
      */
     private $body;
 
@@ -33,7 +33,7 @@ class GearmanMessage implements Message, \JsonSerializable
      */
     private $job;
 
-    public function __construct(string $body = '', array $properties = [], array $headers = [])
+    public function __construct($body = '', array $properties = [], array $headers = [])
     {
         $this->body = $body;
         $this->properties = $properties;
@@ -41,12 +41,12 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
         $this->body = $body;
     }
 
-    public function getBody(): string
+    public function getBody()
     {
         return $this->body;
     }
diff --git a/pkg/gps/GpsContext.php b/pkg/gps/GpsContext.php
index 77e6200cf..6a9081c5e 100644
--- a/pkg/gps/GpsContext.php
+++ b/pkg/gps/GpsContext.php
@@ -61,9 +61,11 @@ public function __construct($client, array $options = [])
     }
 
     /**
+     * @param mixed $body
+     *
      * @return GpsMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new GpsMessage($body, $properties, $headers);
     }
diff --git a/pkg/gps/GpsMessage.php b/pkg/gps/GpsMessage.php
index 5e83e078c..215e67178 100644
--- a/pkg/gps/GpsMessage.php
+++ b/pkg/gps/GpsMessage.php
@@ -10,7 +10,7 @@
 class GpsMessage implements Message, \JsonSerializable
 {
     /**
-     * @var string
+     * @var string|int|float|array|\JsonSerializable
      */
     private $body;
 
@@ -34,7 +34,7 @@ class GpsMessage implements Message, \JsonSerializable
      */
     private $nativeMessage;
 
-    public function __construct(string $body = '', array $properties = [], array $headers = [])
+    public function __construct($body = '', array $properties = [], array $headers = [])
     {
         $this->body = $body;
         $this->properties = $properties;
@@ -43,12 +43,12 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function getBody(): string
+    public function getBody()
     {
         return $this->body;
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
         $this->body = $body;
     }
diff --git a/pkg/mongodb/MongodbContext.php b/pkg/mongodb/MongodbContext.php
index e6f5a579c..af33abf81 100644
--- a/pkg/mongodb/MongodbContext.php
+++ b/pkg/mongodb/MongodbContext.php
@@ -41,9 +41,11 @@ public function __construct($client, array $config = [])
     }
 
     /**
+     * @param mixed $body
+     *
      * @return MongodbMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         $message = new MongodbMessage();
         $message->setBody($body);
diff --git a/pkg/mongodb/MongodbMessage.php b/pkg/mongodb/MongodbMessage.php
index fbfbd75d6..6da34b740 100644
--- a/pkg/mongodb/MongodbMessage.php
+++ b/pkg/mongodb/MongodbMessage.php
@@ -4,19 +4,17 @@
 
 namespace Enqueue\Mongodb;
 
+use Interop\Queue\Impl\StringBodyOnlyTrait;
 use Interop\Queue\Message;
 
 class MongodbMessage implements Message
 {
-    /**
-     * @var string
-     */
-    private $id;
+    use StringBodyOnlyTrait;
 
     /**
      * @var string
      */
-    private $body;
+    private $id;
 
     /**
      * @var array
@@ -75,16 +73,6 @@ public function getId(): ?string
         return $this->id;
     }
 
-    public function setBody(string $body): void
-    {
-        $this->body = $body;
-    }
-
-    public function getBody(): string
-    {
-        return $this->body;
-    }
-
     public function setProperties(array $properties): void
     {
         $this->properties = $properties;
diff --git a/pkg/mongodb/MongodbProducer.php b/pkg/mongodb/MongodbProducer.php
index d27f014eb..4a5e9f5d9 100644
--- a/pkg/mongodb/MongodbProducer.php
+++ b/pkg/mongodb/MongodbProducer.php
@@ -57,8 +57,6 @@ public function send(Destination $destination, Message $message): void
             $message->setTimeToLive($this->timeToLive);
         }
 
-        $body = $message->getBody();
-
         $publishedAt = null !== $message->getPublishedAt() ?
             $message->getPublishedAt() :
             (int) (microtime(true) * 10000)
@@ -66,7 +64,7 @@ public function send(Destination $destination, Message $message): void
 
         $mongoMessage = [
             'published_at' => $publishedAt,
-            'body' => $body,
+            'body' => $message->getBody(),
             'headers' => JSON::encode($message->getHeaders()),
             'properties' => JSON::encode($message->getProperties()),
             'priority' => $message->getPriority(),
diff --git a/pkg/mongodb/Tests/MongodbConsumerTest.php b/pkg/mongodb/Tests/MongodbConsumerTest.php
index e41681256..d11c4e94e 100644
--- a/pkg/mongodb/Tests/MongodbConsumerTest.php
+++ b/pkg/mongodb/Tests/MongodbConsumerTest.php
@@ -131,11 +131,11 @@ private function createContextMock()
 
 class InvalidMessage implements Message
 {
-    public function getBody(): string
+    public function getBody()
     {
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
     }
 
diff --git a/pkg/null/NullContext.php b/pkg/null/NullContext.php
index 5f6001cab..93965395a 100644
--- a/pkg/null/NullContext.php
+++ b/pkg/null/NullContext.php
@@ -16,9 +16,11 @@
 class NullContext implements Context
 {
     /**
+     * @param mixed $body
+     *
      * @return NullMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         $message = new NullMessage();
         $message->setBody($body);
diff --git a/pkg/null/NullMessage.php b/pkg/null/NullMessage.php
index bd48a387e..b733a2d83 100644
--- a/pkg/null/NullMessage.php
+++ b/pkg/null/NullMessage.php
@@ -37,7 +37,7 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
         $this->body = $body;
     }
diff --git a/pkg/pheanstalk/PheanstalkContext.php b/pkg/pheanstalk/PheanstalkContext.php
index 3e2fe834d..2de406619 100644
--- a/pkg/pheanstalk/PheanstalkContext.php
+++ b/pkg/pheanstalk/PheanstalkContext.php
@@ -31,9 +31,11 @@ public function __construct(Pheanstalk $pheanstalk)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return PheanstalkMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new PheanstalkMessage($body, $properties, $headers);
     }
diff --git a/pkg/pheanstalk/PheanstalkMessage.php b/pkg/pheanstalk/PheanstalkMessage.php
index cf4ea1905..995018ad5 100644
--- a/pkg/pheanstalk/PheanstalkMessage.php
+++ b/pkg/pheanstalk/PheanstalkMessage.php
@@ -35,7 +35,7 @@ class PheanstalkMessage implements Message, \JsonSerializable
      */
     private $job;
 
-    public function __construct(string $body = '', array $properties = [], array $headers = [])
+    public function __construct($body = '', array $properties = [], array $headers = [])
     {
         $this->body = $body;
         $this->properties = $properties;
@@ -43,7 +43,7 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
         $this->body = $body;
     }
diff --git a/pkg/rdkafka/RdKafkaContext.php b/pkg/rdkafka/RdKafkaContext.php
index 22d4a8e47..6e99a1207 100644
--- a/pkg/rdkafka/RdKafkaContext.php
+++ b/pkg/rdkafka/RdKafkaContext.php
@@ -57,9 +57,11 @@ public function __construct(array $config)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return RdKafkaMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new RdKafkaMessage($body, $properties, $headers);
     }
diff --git a/pkg/rdkafka/RdKafkaMessage.php b/pkg/rdkafka/RdKafkaMessage.php
index 0785a5644..6d89b4743 100644
--- a/pkg/rdkafka/RdKafkaMessage.php
+++ b/pkg/rdkafka/RdKafkaMessage.php
@@ -10,7 +10,7 @@
 class RdKafkaMessage implements Message
 {
     /**
-     * @var string
+     * @var mixed
      */
     private $body;
 
@@ -44,7 +44,7 @@ class RdKafkaMessage implements Message
      */
     private $kafkaMessage;
 
-    public function __construct(string $body = '', array $properties = [], array $headers = [])
+    public function __construct($body = '', array $properties = [], array $headers = [])
     {
         $this->body = $body;
         $this->properties = $properties;
@@ -52,12 +52,12 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
         $this->body = $body;
     }
 
-    public function getBody(): string
+    public function getBody()
     {
         return $this->body;
     }
diff --git a/pkg/redis/RedisContext.php b/pkg/redis/RedisContext.php
index 344bb20c5..9c974ebdb 100644
--- a/pkg/redis/RedisContext.php
+++ b/pkg/redis/RedisContext.php
@@ -59,9 +59,11 @@ public function __construct($redis, int $redeliveryDelay)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return RedisMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new RedisMessage($body, $properties, $headers);
     }
diff --git a/pkg/redis/RedisMessage.php b/pkg/redis/RedisMessage.php
index 74c65475a..0a8a2415c 100644
--- a/pkg/redis/RedisMessage.php
+++ b/pkg/redis/RedisMessage.php
@@ -9,7 +9,7 @@
 class RedisMessage implements Message
 {
     /**
-     * @var string
+     * @var mixed
      */
     private $body;
 
@@ -38,7 +38,7 @@ class RedisMessage implements Message
      */
     private $key;
 
-    public function __construct(string $body = '', array $properties = [], array $headers = [])
+    public function __construct($body = '', array $properties = [], array $headers = [])
     {
         $this->body = $body;
         $this->properties = $properties;
@@ -47,12 +47,12 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function getBody(): string
+    public function getBody()
     {
         return $this->body;
     }
 
-    public function setBody(string $body): void
+    public function setBody($body): void
     {
         $this->body = $body;
     }
diff --git a/pkg/sns/SnsContext.php b/pkg/sns/SnsContext.php
index b489f8d57..c29d7ebe0 100644
--- a/pkg/sns/SnsContext.php
+++ b/pkg/sns/SnsContext.php
@@ -40,9 +40,11 @@ public function __construct(SnsClient $client, array $config)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return SnsMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new SnsMessage($body, $properties, $headers);
     }
diff --git a/pkg/snsqs/SnsQsContext.php b/pkg/snsqs/SnsQsContext.php
index d520cdb10..c40b2e46d 100644
--- a/pkg/snsqs/SnsQsContext.php
+++ b/pkg/snsqs/SnsQsContext.php
@@ -74,9 +74,11 @@ public function __construct($snsContext, $sqsContext)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return SnsQsMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new SnsQsMessage($body, $properties, $headers);
     }
diff --git a/pkg/sqs/SqsContext.php b/pkg/sqs/SqsContext.php
index 60906f72f..39c1c1e7a 100644
--- a/pkg/sqs/SqsContext.php
+++ b/pkg/sqs/SqsContext.php
@@ -49,9 +49,11 @@ public function __construct(SqsClient $client, array $config)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return SqsMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new SqsMessage($body, $properties, $headers);
     }
diff --git a/pkg/sqs/SqsMessage.php b/pkg/sqs/SqsMessage.php
index 1d9d26bec..0b6c4e533 100644
--- a/pkg/sqs/SqsMessage.php
+++ b/pkg/sqs/SqsMessage.php
@@ -4,14 +4,12 @@
 
 namespace Enqueue\Sqs;
 
+use Interop\Queue\Impl\StringBodyOnlyTrait;
 use Interop\Queue\Message;
 
 class SqsMessage implements Message
 {
-    /**
-     * @var string
-     */
-    private $body;
+    use StringBodyOnlyTrait;
 
     /**
      * @var array
@@ -57,16 +55,6 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->delaySeconds = 0;
     }
 
-    public function setBody(string $body): void
-    {
-        $this->body = $body;
-    }
-
-    public function getBody(): string
-    {
-        return $this->body;
-    }
-
     public function setProperties(array $properties): void
     {
         $this->properties = $properties;
diff --git a/pkg/stomp/StompContext.php b/pkg/stomp/StompContext.php
index e03b11cb6..7819f827b 100644
--- a/pkg/stomp/StompContext.php
+++ b/pkg/stomp/StompContext.php
@@ -43,9 +43,11 @@ public function __construct($stomp)
     }
 
     /**
+     * @param mixed $body
+     *
      * @return StompMessage
      */
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new StompMessage($body, $properties, $headers);
     }
diff --git a/pkg/stomp/StompMessage.php b/pkg/stomp/StompMessage.php
index bb563c8cd..0de6ba262 100644
--- a/pkg/stomp/StompMessage.php
+++ b/pkg/stomp/StompMessage.php
@@ -4,15 +4,13 @@
 
 namespace Enqueue\Stomp;
 
+use Interop\Queue\Impl\StringBodyOnlyTrait;
 use Interop\Queue\Message;
 use Stomp\Transport\Frame;
 
 class StompMessage implements Message
 {
-    /**
-     * @var string
-     */
-    private $body;
+    use StringBodyOnlyTrait;
 
     /**
      * @var array
@@ -42,16 +40,6 @@ public function __construct(string $body = '', array $properties = [], array $he
         $this->redelivered = false;
     }
 
-    public function setBody(string $body): void
-    {
-        $this->body = $body;
-    }
-
-    public function getBody(): string
-    {
-        return $this->body;
-    }
-
     public function setProperties(array $properties): void
     {
         $this->properties = $properties;
diff --git a/pkg/wamp/WampContext.php b/pkg/wamp/WampContext.php
index 9bbed5087..8b28c249e 100644
--- a/pkg/wamp/WampContext.php
+++ b/pkg/wamp/WampContext.php
@@ -38,7 +38,7 @@ public function __construct(callable $clientFactory)
         $this->setSerializer(new JsonSerializer());
     }
 
-    public function createMessage(string $body = '', array $properties = [], array $headers = []): Message
+    public function createMessage($body = '', array $properties = [], array $headers = []): Message
     {
         return new WampMessage($body, $properties, $headers);
     }