diff --git a/src/Bunny/Async/Client.php b/src/Bunny/Async/Client.php
index af4b971..f0929a8 100644
--- a/src/Bunny/Async/Client.php
+++ b/src/Bunny/Async/Client.php
@@ -93,7 +93,7 @@ public function __destruct()
     /**
      * Initializes instance.
      */
-    protected function init()
+    protected function init(): void
     {
         parent::init();
         $this->flushWriteBufferPromise = null;
@@ -106,7 +106,7 @@ protected function init()
      *
      * @param float $maxSeconds
      */
-    public function run($maxSeconds = null)
+    public function run($maxSeconds = null): void
     {
         if ($maxSeconds !== null) {
             $this->stopTimer = $this->eventLoop->addTimer($maxSeconds, function () {
@@ -120,7 +120,7 @@ public function run($maxSeconds = null)
     /**
      * Calls {@link eventLoop}'s stop() method.
      */
-    public function stop()
+    public function stop(): void
     {
         if ($this->stopTimer) {
             $this->eventLoop->cancelTimer($this->stopTimer);
@@ -143,10 +143,8 @@ protected function feedReadBuffer()
      *
      * - Calls {@link eventLoops}'s addWriteStream() with client's stream.
      * - Consecutive calls will return the same instance of promise.
-     *
-     * @return Promise\PromiseInterface
      */
-    protected function flushWriteBuffer()
+    protected function flushWriteBuffer(): Promise\PromiseInterface
     {
         if ($this->flushWriteBufferPromise) {
             return $this->flushWriteBufferPromise;
@@ -179,10 +177,8 @@ protected function flushWriteBuffer()
      * Connects to AMQP server.
      *
      * Calling connect() multiple times will result in error.
-     *
-     * @return Promise\PromiseInterface
      */
-    public function connect()
+    public function connect(): Promise\PromiseInterface
     {
         if ($this->state !== ClientStateEnum::NOT_CONNECTED) {
             return Promise\reject(new ClientException("Client already connected/connecting."));
@@ -233,9 +229,8 @@ public function connect()
      *
      * @param int $replyCode
      * @param string $replyText
-     * @return Promise\PromiseInterface
      */
-    public function disconnect($replyCode = 0, $replyText = "")
+    public function disconnect($replyCode = 0, $replyText = ""): Promise\PromiseInterface
     {
         if ($this->state === ClientStateEnum::DISCONNECTING) {
             return $this->disconnectPromise;
@@ -289,7 +284,7 @@ public function disconnect($replyCode = 0, $replyText = "")
      *
      * @param callable $callback
      */
-    public function addAwaitCallback(callable $callback)
+    public function addAwaitCallback(callable $callback): void
     {
         $this->awaitCallbacks[] = $callback;
     }
@@ -297,7 +292,7 @@ public function addAwaitCallback(callable $callback)
     /**
      * {@link eventLoop}'s read stream callback notifying client that data from server arrived.
      */
-    public function onDataAvailable()
+    public function onDataAvailable(): void
     {
         $this->read();
 
@@ -327,7 +322,7 @@ public function onDataAvailable()
     /**
      * Callback when heartbeat timer timed out.
      */
-    public function onHeartbeat()
+    public function onHeartbeat(): void
     {
         $now = microtime(true);
         $nextHeartbeat = ($this->lastWrite ?: $now) + $this->options["heartbeat"];
@@ -345,5 +340,4 @@ public function onHeartbeat()
             $this->heartbeatTimer = $this->eventLoop->addTimer($nextHeartbeat - $now, [$this, "onHeartbeat"]);
         }
     }
-
 }
diff --git a/src/Bunny/Channel.php b/src/Bunny/Channel.php
index 8dcaddf..5addc91 100644
--- a/src/Bunny/Channel.php
+++ b/src/Bunny/Channel.php
@@ -111,30 +111,24 @@ public function __construct(AbstractClient $client, $channelId)
 
     /**
      * Returns underlying client instance.
-     *
-     * @return AbstractClient
      */
-    public function getClient()
+    public function getClient(): AbstractClient
     {
         return $this->client;
     }
 
     /**
      * Returns channel id.
-     *
-     * @return int
      */
-    public function getChannelId()
+    public function getChannelId(): int
     {
         return $this->channelId;
     }
 
     /**
      * Returns the channel mode.
-     *
-     * @return int
      */
-    public function getMode()
+    public function getMode(): int
     {
         return $this->mode;
     }
@@ -143,9 +137,8 @@ public function getMode()
      * Listener is called whenever 'basic.return' frame is received with arguments (Message $returnedMessage, MethodBasicReturnFrame $frame)
      *
      * @param callable $callback
-     * @return $this
      */
-    public function addReturnListener(callable $callback)
+    public function addReturnListener(callable $callback): self
     {
         $this->removeReturnListener($callback); // remove if previously added to prevent calling multiple times
         $this->returnCallbacks[] = $callback;
@@ -156,9 +149,8 @@ public function addReturnListener(callable $callback)
      * Removes registered return listener. If the callback is not registered, this is noop.
      *
      * @param callable $callback
-     * @return $this
      */
-    public function removeReturnListener(callable $callback)
+    public function removeReturnListener(callable $callback): self
     {
         foreach ($this->returnCallbacks as $k => $v) {
             if ($v === $callback) {
@@ -173,9 +165,8 @@ public function removeReturnListener(callable $callback)
      * Listener is called whenever 'basic.ack' or 'basic.nack' is received.
      *
      * @param callable $callback
-     * @return $this
      */
-    public function addAckListener(callable $callback)
+    public function addAckListener(callable $callback): self
     {
         if ($this->mode !== ChannelModeEnum::CONFIRM) {
             throw new ChannelException("Ack/nack listener can be added when channel in confirm mode.");
@@ -190,9 +181,8 @@ public function addAckListener(callable $callback)
      * Removes registered ack/nack listener. If the callback is not registered, this is noop.
      *
      * @param callable $callback
-     * @return $this
      */
-    public function removeAckListener(callable $callback)
+    public function removeAckListener(callable $callback): self
     {
         if ($this->mode !== ChannelModeEnum::CONFIRM) {
             throw new ChannelException("Ack/nack listener can be removed when channel in confirm mode.");
@@ -214,9 +204,8 @@ public function removeAckListener(callable $callback)
      *
      * @param int $replyCode
      * @param string $replyText
-     * @return PromiseInterface
      */
-    public function close($replyCode = 0, $replyText = "")
+    public function close($replyCode = 0, $replyText = ""): PromiseInterface
     {
         if ($this->state === ChannelStateEnum::CLOSED) {
             throw new ChannelException("Trying to close already closed channel #{$this->channelId}.");
@@ -283,7 +272,7 @@ public function consume(callable $callback, $queue = "", $consumerTag = "", $noL
      * @param bool $nowait
      * @param array $arguments
      */
-    public function run(callable $callback, $queue = "", $consumerTag = "", $noLocal = false, $noAck = false, $exclusive = false, $nowait = false, $arguments = [])
+    public function run(callable $callback, $queue = "", $consumerTag = "", $noLocal = false, $noAck = false, $exclusive = false, $nowait = false, $arguments = []): void
     {
         $response = $this->consume($callback, $queue, $consumerTag, $noLocal, $noAck, $exclusive, $nowait, $arguments);
 
@@ -558,7 +547,7 @@ private function enterConfirmMode(callable $callback = null)
      *
      * @param AbstractFrame $frame
      */
-    public function onFrameReceived(AbstractFrame $frame)
+    public function onFrameReceived(AbstractFrame $frame): void
     {
         if ($this->state === ChannelStateEnum::ERROR) {
             throw new ChannelException("Channel in error state.");
@@ -704,7 +693,7 @@ public function onFrameReceived(AbstractFrame $frame)
     /**
      * Callback after content body has been completely received.
      */
-    protected function onBodyComplete()
+    protected function onBodyComplete(): void
     {
         if ($this->returnFrame) {
             $content = $this->bodyBuffer->consume($this->bodyBuffer->getLength());
diff --git a/src/Bunny/Client.php b/src/Bunny/Client.php
index bde19ab..bc60865 100644
--- a/src/Bunny/Client.php
+++ b/src/Bunny/Client.php
@@ -67,10 +67,8 @@ public function __destruct()
 
     /**
      * Reads data from stream to {@link readBuffer}.
-     *
-     * @return boolean
      */
-    protected function feedReadBuffer()
+    protected function feedReadBuffer(): bool
     {
         $this->read();
         return true;
@@ -78,10 +76,8 @@ protected function feedReadBuffer()
 
     /**
      * Writes all data from {@link writeBuffer} to stream.
-     *
-     * @return boolean
      */
-    protected function flushWriteBuffer()
+    protected function flushWriteBuffer(): bool
     {
         while (!$this->writeBuffer->isEmpty()) {
             $this->write();
@@ -93,9 +89,8 @@ protected function flushWriteBuffer()
      * Synchronously connects to AMQP server.
      *
      * @throws \Exception
-     * @return self
      */
-    public function connect()
+    public function connect(): self
     {
         if ($this->state !== ClientStateEnum::NOT_CONNECTED) {
             throw new ClientException("Client already connected/connecting.");
@@ -130,9 +125,9 @@ public function connect()
      *
      * @param int $replyCode
      * @param string $replyText
-     * @return Promise\PromiseInterface
+     * @return
      */
-    public function disconnect($replyCode = 0, $replyText = "")
+    public function disconnect($replyCode = 0, $replyText = ""): Promise\PromiseInterface
     {
         if ($this->state === ClientStateEnum::DISCONNECTING) {
             return $this->disconnectPromise;
@@ -169,7 +164,7 @@ public function disconnect($replyCode = 0, $replyText = "")
      *
      * @param float $maxSeconds
      */
-    public function run($maxSeconds = null)
+    public function run($maxSeconds = null): void
     {
         if (!$this->isConnected()) {
             throw new ClientException("Client has to be connected.");
@@ -263,7 +258,7 @@ public function run($maxSeconds = null)
     /**
      * Stops client's event loop.
      */
-    public function stop()
+    public function stop(): void
     {
         $this->running = false;
     }