diff --git a/src/Message.php b/src/Message.php
index e39f13a..12d0dc5 100644
--- a/src/Message.php
+++ b/src/Message.php
@@ -28,6 +28,7 @@ class Message implements \JsonSerializable
     private $recipientType;
     private $timeToLive;
     private $delayWhileIdle;
+    private $restrictedPackageName;
 
     /**
      * Represents the app's "Send-to-Sync" message.
@@ -69,6 +70,21 @@ public function setNotification(Notification $notification)
         return $this;
     }
 
+    /**
+     * Custom package name
+     *
+     * @see https://firebase.google.com/docs/cloud-messaging/http-server-ref#table1
+     *
+     * @param string $package_name
+     *
+     * @return \paragraph1\phpFCM\Message
+     */
+    public function setRestrictedPackageName($package_name)
+    {
+        $this->restrictedPackageName = $package_name;
+        return $this;
+    }
+
     /**
      * @see https://firebase.google.com/docs/cloud-messaging/concept-options#collapsible_and_non-collapsible_messages
      *
@@ -169,6 +185,9 @@ public function jsonSerialize()
         if ($this->contentAvailableFlag === TRUE) {
             $jsonData['content_available'] = TRUE;
         }
+        if ($this->restrictedPackageName) {
+            $jsonData['restricted_package_name'] = $this->restrictedPackageName;
+        }
 
         return $jsonData;
     }
diff --git a/src/Notification.php b/src/Notification.php
index 812444d..ff07951 100644
--- a/src/Notification.php
+++ b/src/Notification.php
@@ -138,7 +138,7 @@ public function jsonSerialize()
 
         $jsonData['body'] = $this->body;
 
-        if ($this->badge) {
+        if (is_int($this->badge)) {
             $jsonData['badge'] = $this->badge;
         }
         if ($this->icon) {