diff --git a/src/Centrifugo.php b/src/Centrifugo.php
index 438b750655f4dfabb5c2765880acaee0d3d0f368..d127606f99118f286316f6a54f048706008552ff 100644
--- a/src/Centrifugo.php
+++ b/src/Centrifugo.php
@@ -42,7 +42,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return array
      */
-    protected function initConfiguration(array $config) : array
+    protected function initConfiguration(array $config): array
     {
         $defaults = [
             'url'                   => 'http://localhost:8000',
@@ -70,7 +70,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function publish(string $channel, array $data, $skipHistory = false) : array
+    public function publish(string $channel, array $data, $skipHistory = false): array
     {
         return $this->send('publish', [
             'channel'      => $channel,
@@ -88,7 +88,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function broadcast(array $channels, array $data, $skipHistory = false) : array
+    public function broadcast(array $channels, array $data, $skipHistory = false): array
     {
         $params = [
             'channels'     => $channels,
@@ -106,7 +106,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function presence(string $channel) : array
+    public function presence(string $channel): array
     {
         return $this->send('presence', ['channel' => $channel]);
     }
@@ -118,7 +118,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function presenceStats(string $channel) : array
+    public function presenceStats(string $channel): array
     {
         return $this->send('presence_stats', ['channel' => $channel]);
     }
@@ -133,7 +133,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function history(string $channel, $limit = 0, $since = [], $reverse = false) : array
+    public function history(string $channel, $limit = 0, $since = [], $reverse = false): array
     {
         $params = [
             'channel' => $channel,
@@ -154,7 +154,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function historyRemove(string $channel) : array
+    public function historyRemove(string $channel): array
     {
         return $this->send('history_remove', [
             'channel' => $channel,
@@ -170,7 +170,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function subscribe($channel, $user, $client = '') : array
+    public function subscribe($channel, $user, $client = ''): array
     {
         return $this->send('subscribe', [
             'channel' => $channel,
@@ -188,7 +188,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function unsubscribe(string $channel, string $user, string $client = '') : array
+    public function unsubscribe(string $channel, string $user, string $client = ''): array
     {
         return $this->send('unsubscribe', [
             'channel' => $channel,
@@ -204,7 +204,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function disconnect(string $user_id, string $client = '') : array
+    public function disconnect(string $user_id, string $client = ''): array
     {
         return $this->send('disconnect', [
             'user'   => $user_id,
@@ -219,7 +219,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function channels(string $pattern = '') : array
+    public function channels(string $pattern = ''): array
     {
         return $this->send('channels', ['pattern' => $pattern]);
     }
@@ -229,7 +229,7 @@ class Centrifugo implements CentrifugoInterface
      *
      * @return mixed
      */
-    public function info() : array
+    public function info(): array
     {
         return $this->send('info');
     }
@@ -323,10 +323,11 @@ class Centrifugo implements CentrifugoInterface
      * @param string $method
      * @param array  $params
      *
-     * @return mixed
      * @throws GuzzleException
+     *
+     * @return mixed
      */
-    protected function send($method, array $params = []) : array
+    protected function send($method, array $params = []): array
     {
         $json = json_encode(['method' => $method, 'params' => $params]);