diff --git a/AmqpConnectionFactory.php b/AmqpConnectionFactory.php
index 4a780c1..505f753 100644
--- a/AmqpConnectionFactory.php
+++ b/AmqpConnectionFactory.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Enqueue\AmqpLib;
 
 use Enqueue\AmqpTools\ConnectionConfig;
diff --git a/AmqpConsumer.php b/AmqpConsumer.php
index b16dd60..70071fb 100644
--- a/AmqpConsumer.php
+++ b/AmqpConsumer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Enqueue\AmqpLib;
 
 use Interop\Amqp\AmqpConsumer as InteropAmqpConsumer;
diff --git a/AmqpContext.php b/AmqpContext.php
index 4e24fe9..7a97720 100644
--- a/AmqpContext.php
+++ b/AmqpContext.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Enqueue\AmqpLib;
 
 use Enqueue\AmqpTools\DelayStrategyAware;
diff --git a/AmqpProducer.php b/AmqpProducer.php
index 346c07a..6d7f2de 100644
--- a/AmqpProducer.php
+++ b/AmqpProducer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Enqueue\AmqpLib;
 
 use Enqueue\AmqpTools\DelayStrategyAware;
diff --git a/AmqpSubscriptionConsumer.php b/AmqpSubscriptionConsumer.php
index efb4d32..45feda5 100644
--- a/AmqpSubscriptionConsumer.php
+++ b/AmqpSubscriptionConsumer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Enqueue\AmqpLib;
 
 use Enqueue\AmqpTools\SignalSocketHelper;
diff --git a/Buffer.php b/Buffer.php
deleted file mode 100644
index 2773280..0000000
--- a/Buffer.php
+++ /dev/null
@@ -1,43 +0,0 @@
-<?php
-
-namespace Enqueue\AmqpLib;
-
-use Interop\Amqp\AmqpMessage;
-
-class Buffer
-{
-    /**
-     * @var array ['aTag' => [AmqpMessage, AmqpMessage ...]]
-     */
-    private $messages;
-
-    public function __construct()
-    {
-        $this->messages = [];
-    }
-
-    /**
-     * @param string      $consumerTag
-     * @param AmqpMessage $message
-     */
-    public function push($consumerTag, AmqpMessage $message)
-    {
-        if (false == array_key_exists($consumerTag, $this->messages)) {
-            $this->messages[$consumerTag] = [];
-        }
-
-        $this->messages[$consumerTag][] = $message;
-    }
-
-    /**
-     * @param string $consumerTag
-     *
-     * @return AmqpMessage|null
-     */
-    public function pop($consumerTag)
-    {
-        if (false == empty($this->messages[$consumerTag])) {
-            return array_shift($this->messages[$consumerTag]);
-        }
-    }
-}
diff --git a/StopBasicConsumptionException.php b/StopBasicConsumptionException.php
index 14d6848..99c9ea1 100644
--- a/StopBasicConsumptionException.php
+++ b/StopBasicConsumptionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Enqueue\AmqpLib;
 
 class StopBasicConsumptionException extends \LogicException
diff --git a/Tests/BufferTest.php b/Tests/BufferTest.php
deleted file mode 100644
index bebe435..0000000
--- a/Tests/BufferTest.php
+++ /dev/null
@@ -1,64 +0,0 @@
-<?php
-
-namespace Enqueue\AmqpLib\Tests;
-
-use Enqueue\AmqpLib\Buffer;
-use Interop\Amqp\Impl\AmqpMessage;
-use PHPUnit\Framework\TestCase;
-
-class BufferTest extends TestCase
-{
-    public function testCouldBeConstructedWithoutAnyArguments()
-    {
-        new Buffer();
-    }
-
-    public function testShouldSetEmptyArrayToMessagesPropertyOnConstruct()
-    {
-        $buffer = new Buffer();
-
-        $this->assertAttributeSame([], 'messages', $buffer);
-    }
-
-    public function testShouldReturnNullIfNoMessagesInBuffer()
-    {
-        $buffer = new Buffer();
-
-        $this->assertNull($buffer->pop('aConsumerTag'));
-        $this->assertNull($buffer->pop('anotherConsumerTag'));
-    }
-
-    public function testShouldPushMessageToBuffer()
-    {
-        $fooMessage = new AmqpMessage();
-        $barMessage = new AmqpMessage();
-        $bazMessage = new AmqpMessage();
-
-        $buffer = new Buffer();
-
-        $buffer->push('aConsumerTag', $fooMessage);
-        $buffer->push('aConsumerTag', $barMessage);
-
-        $buffer->push('anotherConsumerTag', $bazMessage);
-
-        $this->assertAttributeSame([
-            'aConsumerTag' => [$fooMessage, $barMessage],
-            'anotherConsumerTag' => [$bazMessage],
-        ], 'messages', $buffer);
-    }
-
-    public function testShouldPopMessageFromBuffer()
-    {
-        $fooMessage = new AmqpMessage();
-        $barMessage = new AmqpMessage();
-
-        $buffer = new Buffer();
-
-        $buffer->push('aConsumerTag', $fooMessage);
-        $buffer->push('aConsumerTag', $barMessage);
-
-        $this->assertSame($fooMessage, $buffer->pop('aConsumerTag'));
-        $this->assertSame($barMessage, $buffer->pop('aConsumerTag'));
-        $this->assertNull($buffer->pop('aConsumerTag'));
-    }
-}