diff --git a/composer.json b/composer.json
index d8f8b35..726d3f0 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,7 @@
         "illuminate/notifications": "~6.0 || ~7.0 || ~8.0",
         "illuminate/support": "~6.0 || ~7.0 || ~8.0",
         "illuminate/events": "~6.0 || ~7.0 || ~8.0",
-        "plivo/plivo-php": "^1.1"
+        "plivo/plivo-php": "^1.1 || ^4.0"
     },
     "require-dev": {
         "mockery/mockery": "^1.3",
diff --git a/src/Plivo.php b/src/Plivo.php
index 7b0b8e0..d3911dc 100644
--- a/src/Plivo.php
+++ b/src/Plivo.php
@@ -2,9 +2,9 @@
 
 namespace NotificationChannels\Plivo;
 
-use Plivo\RestAPI as PlivoRestApi;
+use Plivo\RestClient;
 
-class Plivo extends PlivoRestApi
+class Plivo extends RestClient
 {
     /** @var string */
     protected $auth_id;
diff --git a/src/PlivoChannel.php b/src/PlivoChannel.php
index eb36c11..3a43768 100644
--- a/src/PlivoChannel.php
+++ b/src/PlivoChannel.php
@@ -4,11 +4,12 @@
 
 use Illuminate\Notifications\Notification;
 use NotificationChannels\Plivo\Exceptions\CouldNotSendNotification;
+use Plivo\Resources\Message\MessageCreateResponse;
 
 class PlivoChannel
 {
     /**
-     * @var \NotificationChannels\Plivo\Plivo;
+     * @var Plivo;
      */
     protected $plivo;
 
@@ -31,15 +32,16 @@ public function __construct(Plivo $plivo)
     /**
      * Send the given notification.
      *
-     * @param mixed $notifiable
+     * @param mixed                                  $notifiable
      * @param \Illuminate\Notifications\Notification $notification
      *
-     * @throws \NotificationChannels\Plivo\Exceptions\CouldNotSendNotification
+     * @return MessageCreateResponse|null
+     * @throws CouldNotSendNotification
      */
     public function send($notifiable, Notification $notification)
     {
-        if (! $to = $notifiable->routeNotificationFor('plivo')) {
-            return;
+        if (!$to = $notifiable->routeNotificationFor('plivo')) {
+            return null;
         }
 
         $message = $notification->toPlivo($notifiable);
@@ -48,13 +50,14 @@ public function send($notifiable, Notification $notification)
             $message = new PlivoMessage($message);
         }
 
-        $response = $this->plivo->send_message([
-            'src' => $message->from ?: $this->from,
-            'dst' => $to,
-            'text' => trim($message->content),
-        ]);
+        /** @var MessageCreateResponse $response */
+        $response = $this->plivo->messages->create(
+            $message->from ?: $this->from,
+            $to,
+            trim($message->content)
+        );
 
-        if ($response['status'] !== 202) {
+        if ($response->getStatusCode() > 400) {
             throw CouldNotSendNotification::serviceRespondedWithAnError($response);
         }