diff --git a/lib/Ratchet/Application/WAMP/App.php b/lib/Ratchet/Application/WAMP/App.php
index 6d9c002..776bbba 100644
--- a/lib/Ratchet/Application/WAMP/App.php
+++ b/lib/Ratchet/Application/WAMP/App.php
@@ -23,8 +23,19 @@ use Ratchet\Application\WAMP\Command\Action\Prefix;
  * | EVENT        | 8  | Server-to-Client |
  * +--------------+----+------------------+
  * @link http://www.tavendo.de/autobahn/protocol.html
+ * @link https://raw.github.com/oberstet/Autobahn/master/lib/javascript/autobahn.js
  */
 class App implements WebSocketAppInterface {
+    const MSG_WELCOME     = 0;
+    const MSG_PREFIX      = 1;
+    const MSG_CALL        = 2;
+    const MSG_CALL_RESULT = 3;
+    const MSG_CALL_ERROR  = 4;
+    const MSG_SUBSCRIBE   = 5;
+    const MSG_UNSUBSCRIBE = 6;
+    const MSG_PUBLISH     = 7;
+    const MSG_EVENT       = 8;
+
     protected $_app;
 
     /**
@@ -81,11 +92,11 @@ class App implements WebSocketAppInterface {
         }
 
         switch ($json[0]) {
-            case 1:
+            case static::MSG_PREFIX:
                 $ret = $this->addPrefix($from, $json[1], $json[2]);
             break;
 
-            case 2:
+            case static::MSG_CALL:
                 array_shift($json);
                 $callID  = array_shift($json);
                 $procURI = array_shift($json);
@@ -97,15 +108,15 @@ class App implements WebSocketAppInterface {
                 $ret = $this->_app->onCall($from, $callID, $procURI, $json);
             break;
 
-            case 5:
+            case static::MSG_SUBSCRIBE:
                 $ret = $this->_app->onSubscribe($from, $this->getUri($from, $json[1]));
             break;
 
-            case 6:
+            case static::MSG_UNSUBSCRIBE:
                 $ret = $this->_app->onUnSubscribe($from, $this->getUri($from, $json[1]));
             break;
 
-            case 7:
+            case static::MSG_PUBLISH:
                 $ret = $this->_app->onPublish($from, $this->getUri($from, $json[1]), $json[2]);
             break;
 
diff --git a/lib/Ratchet/Application/WAMP/Command/Action/CallError.php b/lib/Ratchet/Application/WAMP/Command/Action/CallError.php
index afba2b2..6938dc1 100644
--- a/lib/Ratchet/Application/WAMP/Command/Action/CallError.php
+++ b/lib/Ratchet/Application/WAMP/Command/Action/CallError.php
@@ -1,6 +1,7 @@
 <?php
 namespace Ratchet\Application\WAMP\Command\Action;
 use Ratchet\Resource\Command\Action\SendMessage;
+use Ratchet\Application\WAMP\App as WAMP;
 
 class CallError extends SendMessage {
     protected $_id;
@@ -14,7 +15,7 @@ class CallError extends SendMessage {
         $this->_uri  = $uri;
         $this->_desc = $desc;
 
-        return $this->setMessage(json_encode(array(4, $callId, $uri, $desc)));
+        return $this->setMessage(json_encode(array(WAMP::MSG_CALL_ERROR, $callId, $uri, $desc)));
     }
 
     public function getId() {
diff --git a/lib/Ratchet/Application/WAMP/Command/Action/CallResult.php b/lib/Ratchet/Application/WAMP/Command/Action/CallResult.php
index 5e41a8a..e839567 100644
--- a/lib/Ratchet/Application/WAMP/Command/Action/CallResult.php
+++ b/lib/Ratchet/Application/WAMP/Command/Action/CallResult.php
@@ -1,6 +1,7 @@
 <?php
 namespace Ratchet\Application\WAMP\Command\Action;
 use Ratchet\Resource\Command\Action\SendMessage;
+use Ratchet\Application\WAMP\App as WAMP;
 
 /**
  */
@@ -13,7 +14,7 @@ class CallResult extends SendMessage {
         $this->_id   = $callId;
         $this->_data = $data;
 
-        return $this->setMessage(json_encode(array(3, $callId, $data)));
+        return $this->setMessage(json_encode(array(WAMP::MSG_CALL_RESULT, $callId, $data)));
     }
 
     public function getId() {
diff --git a/lib/Ratchet/Application/WAMP/Command/Action/Event.php b/lib/Ratchet/Application/WAMP/Command/Action/Event.php
index fac4428..6ec8813 100644
--- a/lib/Ratchet/Application/WAMP/Command/Action/Event.php
+++ b/lib/Ratchet/Application/WAMP/Command/Action/Event.php
@@ -1,6 +1,7 @@
 <?php
 namespace Ratchet\Application\WAMP\Command\Action;
 use Ratchet\Resource\Command\Action\SendMessage;
+use Ratchet\Application\WAMP\App as WAMP;
 
 /**
  * This is an event in the context of a topicURI
@@ -13,6 +14,6 @@ class Event extends SendMessage {
      * @return Event
      */
     public function setEvent($uri, $msg) {
-        return $this->setMessage(json_encode(array(8, $uri, (string)$msg)));
+        return $this->setMessage(json_encode(array(WAMP::MSG_EVENT, $uri, (string)$msg)));
     }
 }
\ No newline at end of file
diff --git a/lib/Ratchet/Application/WAMP/Command/Action/Prefix.php b/lib/Ratchet/Application/WAMP/Command/Action/Prefix.php
index 627dce2..a66a033 100644
--- a/lib/Ratchet/Application/WAMP/Command/Action/Prefix.php
+++ b/lib/Ratchet/Application/WAMP/Command/Action/Prefix.php
@@ -1,6 +1,7 @@
 <?php
 namespace Ratchet\Application\WAMP\Command\Action;
 use Ratchet\Resource\Command\Action\SendMessage;
+use Ratchet\Application\WAMP\App as WAMP;
 
 /**
  * Send a curie to uri mapping to the client
@@ -20,7 +21,7 @@ class Prefix extends SendMessage {
         $this->_curie = $curie;
         $this->_uri   = $uri;
 
-        return $this->setMessage(json_encode(array(1, $curie, $uri)));
+        return $this->setMessage(json_encode(array(WAMP::MSG_PREFIX, $curie, $uri)));
     }
 
     /**